10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C.  20549

FORM 10-Q

QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d)

OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended:  September 30, 2017

Commission File Number:  000-29274

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

(Exact name of registrant as specified in its charter)

State of Minnesota	41-1789725
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)
30 East 7th Street, Suite 1300 St. Paul, Minnesota 55101	(651) 227-7333
(Address of principal executive offices)	(Registrant's telephone number)

Not Applicable

(Former name, former address and former fiscal year, if changed since last report)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.     ☒ Yes    ☐ No

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).     ☒ Yes    ☐ No

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company.  See the definitions of "large accelerated filer," "accelerated filer" and "smaller reporting company" in Rule 12b-2 of the Exchange Act.

☐ Large accelerated filer	☐ Accelerated filer
☐ Non-accelerated filer	☒ Smaller reporting company
☐ Emerging growth company

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.     ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).     ☐ Yes    ☒ No

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

INDEX

				Page
Part I – Financial Information
	Item 1.	Financial Statements:
		Balance Sheets as of September 30, 2017 and December 31, 2016		3
		Statements for the Periods ended September 30, 2017 and 2016:
			Income	4
			Cash Flows	5
			Changes in Partners' Capital (Deficit)	6
		Notes to Financial Statements		7 - 10
	Item 2.	Management's Discussion and Analysis of Financial
			Condition and Results of Operations	11 - 16
	Item 3.	Quantitative and Qualitative Disclosures About Market Risk		16
	Item 4.	Controls and Procedures		16
Part II – Other Information
	Item 1.	Legal Proceedings		17
	Item 1A.	Risk Factors		17
	Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds		17
	Item 3.	Defaults Upon Senior Securities		17
	Item 4.	Mine Safety Disclosures		17
	Item 5.	Other Information		17
	Item 6.	Exhibits		18
Signatures				18

Page 2 of 18

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

BALANCE SHEETS

ASSETS

	September 30,			December 31,
	2017			2016
	(unaudited)
Current Assets:
Cash	$	502,495		$	691,125
Real Estate Investments:
Land		3,659,461			3,839,216
Buildings		10,339,539			11,377,241
Acquired Intangible Lease Assets		807,178			807,178
Real Estate Held for Investment, at cost		14,806,178			16,023,635
Accumulated Depreciation and Amortization		(3,651,584	)		(3,650,418	)
Real Estate Held for Investment, Net		11,154,594			12,373,217
Real Estate Held for Sale		652,572			0
Total Real Estate Investments		11,807,166			12,373,217
Total Assets	$	12,309,661		$	13,064,342

LIABILITIES AND PARTNERS' CAPITAL

Current Liabilities:
Payable to AEI Fund Management, Inc.	$	238		$	27,151
Distributions Payable		208,282			261,212
Unearned Rent		34,520			12,121
Total Current Liabilities		243,040			300,484
Long-term Liabilities:
Acquired Below-Market Lease Intangibles, Net		111,530			125,855
Partners' Capital (Deficit):
General Partners		(25,382	)		(18,553	)
Limited Partners – 24,000 Units authorized;    19,616 and 19,636 Units issued and outstanding    as of 9/30/17 and 12/31/16, respectively		11,980,473			12,656,556
Total Partners' Capital		11,955,091			12,638,003
Total Liabilities and Partners' Capital	$	12,309,661		$	13,064,342

The accompanying Notes to Financial Statements are an integral part of these statements.

Page 3 of 18

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

STATEMENTS OF INCOME

(unaudited)

	Three Months Ended September 30				Nine Months Ended September 30
	2017		2016		2017		2016
Rental Income	$	292,215	$	328,755	$	924,167	$	971,456
Expenses:
Partnership Administration – Affiliates		41,384		41,010		128,126		127,367
Partnership Administration and Property    Management – Unrelated Parties		51,348		7,891		88,753		40,075
Property Acquisition		0		27		0		56,760
Depreciation and Amortization		117,621		132,964		642,801		389,933
Total Expenses		210,353		181,892		859,680		614,135
Operating Income		81,862		146,863		64,487		357,321
Other Income:
Interest Income		302		549		1,097		2,361
Net Income	$	82,164	$	147,412	$	65,584	$	359,682
Net Income Allocated:
General Partners	$	822	$	1,474	$	656	$	3,597
Limited Partners		81,342		145,938		64,928		356,085
Total	$	82,164	$	147,412	$	65,584	$	359,682
Net Income per Limited Partnership Unit	$	4.15	$	7.36	$	3.31	$	17.87
Weighted Average Units Outstanding –       Basic and Diluted		19,616		19,841		19,622		19,929

The accompanying Notes to Financial Statements are an integral part of these statements.

Page 4 of 18

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

STATEMENTS OF CASH FLOWS

(unaudited)

	Nine Months Ended September 30
	2017			2016
Cash Flows from Operating Activities:
Net Income	$	65,584		$	359,682
Adjustments to Reconcile Net Income To Net Cash Provided by Operating Activities:
Depreciation and Amortization		628,476			376,959
Increase (Decrease) in Payable to    AEI Fund Management, Inc.		(26,913	)		6,829
Increase (Decrease) in Unearned Rent		22,399			22,400
Total Adjustments		623,962			406,188
Net Cash Provided By (Used For)    Operating Activities		689,546			765,870
Cash Flows from Investing Activities:
Investments in Real Estate		(76,750	)		(1,809,915	)
Cash Flows from Financing Activities:
Distributions Paid to Partners		(783,632	)		(789,501	)
Repurchase of Partnership Units		(17,794	)		(235,431	)
Net Cash Provided By (Used For)    Financing Activities		(801,426	)		(1,024,932	)
Net Increase (Decrease) in Cash		(188,630	)		(2,068,977	)
Cash, beginning of period		691,125			2,925,122
Cash, end of period	$	502,495		$	856,145

The accompanying Notes to Financial Statements are an integral part of these statements.

Page 5 of 18

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

STATEMENTS OF CHANGES IN PARTNERS' CAPITAL (DEFICIT)

(unaudited)

	General Partners			Limited Partners			Total			Limited Partnership Units Outstanding
Balance, December 31, 2015	$	(9,126	)	$	13,589,851		$	13,580,725			20,104.88
Distributions Declared		(7,866	)		(778,703	)		(786,569	)
Repurchase of Partnership Units		(2,355	)		(233,076	)		(235,431	)		(264.01	)
Net Income		3,597			356,085			359,682
Balance, September 30, 2016	$	(15,750	)	$	12,934,157		$	12,918,407			19,840.87
Balance, December 31, 2016	$	(18,553	)	$	12,656,556		$	12,638,003			19,635.64
Distributions Declared		(7,307	)		(723,395	)		(730,702	)
Repurchase of Partnership Units		(178	)		(17,616	)		(17,794	)		(20.00	)
Net Income		656			64,928			65,584
Balance, September 30, 2017	$	(25,382	)	$	11,980,473		$	11,955,091			19,615.64

The accompanying Notes to Financial Statements are an integral part of these statements.

Page 6 of 18

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

NOTES TO FINANCIAL STATEMENTS

SEPTEMBER 30, 2017

(unaudited)

(1)  The condensed statements included herein have been prepared by the registrant, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission, and reflect all adjustments which are, in the opinion of management, necessary to a fair statement of the results of operations for the interim period, on a basis consistent with the annual audited statements.  The adjustments made to these condensed statements consist only of normal recurring adjustments.  Certain information, accounting policies, and footnote disclosures normally included in financial statements prepared in accordance with United States Generally Accepted Accounting Principles (US GAAP) have been condensed or omitted pursuant to such rules and regulations, although the registrant believes that the disclosures are adequate to make the information presented not misleading.  It is suggested that these condensed financial statements be read in conjunction with the financial statements and the summary of significant accounting policies and notes thereto included in the registrant's latest annual report on Form 10‑K.

(2)  Organization –

AEI Income & Growth Fund XXI Limited Partnership ("Partnership") was formed to acquire and lease commercial properties to operating tenants.  The Partnership's operations are managed by AEI Fund Management XXI, Inc. ("AFM"), the Managing General Partner.  Robert P. Johnson, the President and sole director of AFM, serves as the Individual General Partner.  AFM is a wholly owned subsidiary of AEI Capital Corporation of which Mr. Johnson is the majority shareholder.  AEI Fund Management, Inc. ("AEI"), an affiliate of AFM, performs the administrative and operating functions for the Partnership.

The terms of the Partnership offering called for a subscription price of $1,000 per Limited Partnership Unit, payable on acceptance of the offer.  The Partnership commenced operations on April 14, 1995 when minimum subscriptions of 1,500 Limited Partnership Units ($1,500,000) were accepted.  On January 31, 1997, the offering terminated when the maximum subscription limit of 24,000 Limited Partnership Units was reached.  Under the terms of the Limited Partnership Agreement, the Limited Partners and General Partners contributed funds of $24,000,000 and $1,000, respectively.

During operations, any Net Cash Flow, as defined, which the General Partners determine to distribute will be distributed 90% to the Limited Partners and 10% to the General Partners; provided, however, that such distributions to the General Partners will be subordinated to the Limited Partners first receiving an annual, noncumulative distribution of Net Cash Flow equal to 10% of their Adjusted Capital Contribution, as defined, and, provided further, that in no event will the General Partners receive less than 1% of such Net Cash Flow per annum.  Distributions to Limited Partners will be made pro rata by Units.

Page 7 of 18

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

NOTES TO FINANCIAL STATEMENTS

(Continued)

(2)  Organization – (Continued)

Any Net Proceeds of Sale, as defined, from the sale or financing of properties which the General Partners determine to distribute will, after provisions for debts and reserves, be paid in the following manner: (i) first, 99% to the Limited Partners and 1% to the General Partners until the Limited Partners receive an amount equal to: (a) their Adjusted Capital Contribution plus (b) an amount equal to 10% of their Adjusted Capital Contribution per annum, cumulative but not compounded, to the extent not previously distributed from Net Cash Flow;  (ii) any remaining balance will be distributed 90% to the Limited Partners and 10% to the General Partners.  Distributions to the Limited Partners will be made pro rata by Units.

For tax purposes, profits from operations, other than profits attributable to the sale, exchange, financing, refinancing or other disposition of property, will be allocated first in the same ratio in which, and to the extent, Net Cash Flow is distributed to the Partners for such year.  Any additional profits will be allocated in the same ratio as the last dollar of Net Cash Flow is distributed.  Net losses from operations will be allocated 99% to the Limited Partners and 1% to the General Partners.

For tax purposes, profits arising from the sale, financing, or other disposition of property will be allocated in accordance with the Partnership Agreement as follows: (i) first, to those partners with deficit balances in their capital accounts in an amount equal to the sum of such deficit balances; (ii) second, 99% to the Limited Partners and 1% to the General Partners until the aggregate balance in the Limited Partners' capital accounts equals the sum of the Limited Partners' Adjusted Capital Contributions plus an amount equal to 10% of their Adjusted Capital Contributions per annum, cumulative but not compounded, to the extent not previously allocated; (iii) third, the balance of any remaining gain will then be allocated 90% to the Limited Partners and 10% to the General Partners.  Losses will be allocated 98% to the Limited Partners and 2% to the General Partners.

The General Partners are not required to currently fund a deficit capital balance.  Upon liquidation of the Partnership or withdrawal by a General Partner, the General Partners will contribute to the Partnership an amount equal to the lesser of the deficit balances in their capital accounts or 1% of total Limited Partners' and General Partners' capital contributions.

In January 2014, the Managing General Partner mailed a Consent Statement (Proxy) seeking the consent of the Limited Partners to continue the Partnership for an additional 60 months or to initiate the final disposition, liquidation and distribution of all of the Partnership's properties and assets.  On February 14, 2014, the proposal to continue the Partnership was approved with a majority of Units voted in favor of the continuation proposal.  As a result, the Managing General Partner will continue the operations of the Partnership for an additional 60 months at which time it will again ask the Limited Partners to vote on the same two proposals.

Page 8 of 18

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

NOTES TO FINANCIAL STATEMENTS

(Continued)

(3)  Real Estate Investments –

On February 3, 2016, the Partnership purchased a Dollar Tree store in Cincinnati, Ohio for $1,809,915.  The Partnership allocated $285,049 of the purchase price to Acquired Intangible Lease Assets, representing in-place lease intangibles, and allocated $80,404 to Acquired Below-Market Lease Intangibles. The Partnership incurred $56,760 of acquisition expenses related to the purchase that were expensed.  The property is leased to Dollar Tree Stores, Inc. under a lease agreement with a remaining primary term of 10 years (as of the date of purchase) and annual rent of $122,169.

The Partnership owns a 30% interest in the Gander Mountain store in Champaign, Illinois.  The remaining interests in the property are owned by affiliates of the Partnership.  On March 10, 2017, Gander Mountain Company filed for Chapter 11 reorganization and announced it was closing the store, following a liquidation sale of its on‑site assets.  In June 2017, the tenant filed a motion with the bankruptcy court to reject the lease for this store effective June 30, 2017.  At this time, the tenant returned possession of the property to the owners and the Partnership became responsible for its 30% share of real estate taxes and other costs associated with maintaining the property.  The tenant paid rent through June 2017.  The owners have listed the property for lease with a real estate broker in the Champaign area.  The annual rent from this property represented approximately 13% of the total annual rent of the Partnership's property portfolio.  The loss of rent and increased expenses related to this property decreased the Partnership's cash flow.  Consequently, beginning with the third quarter of 2017, the Partnership reduced its regular quarterly cash distribution rate from $13.18 per Unit to $10.51 per Unit.

As a result of the bankruptcy court terminating the lease for the Gander Mountain store, the Partnership included an additional $270,097 in Depreciation and Amortization in the second quarter of 2017, which represented the unamortized balance of the in-place lease intangible that was created when the property was purchased in 2014.

In March 2017, the Partnership entered into an agreement with the tenant of the KinderCare daycare center in Andover, Minnesota to extend the lease term five years to expire on June 30, 2022.  The annual rent will remain the same throughout the remainder of the extended lease term.  As part of the agreement, the Partnership paid a tenant improvement allowance of $30,000 that was capitalized.  In addition, beginning on April 1, 2017, the tenant received free rent for three months that equaled $36,362.  In the first quarter of 2017, the Partnership decided to sell the property.  At September 30, 2017, the property was classified as Real Estate Held for Sale with a carrying value of $652,572.

In October 2017, the Partnership entered into an agreement to sell the KinderCare to an unrelated third party.  The sale is subject to contingencies and may not be completed.  If the sale is completed, the Partnership expects to receive net proceeds of approximately $1,695,000, which will result in a net gain of approximately $1,042,400.

Page 9 of 18

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

NOTES TO FINANCIAL STATEMENTS

(Continued)

(3)  Real Estate Investments – (Continued)

In April 2017, the Partnership entered into an agreement with the tenant of the Fresenius Medical Center in Shreveport, Louisiana to extend the lease term nine years to expire on June 30, 2027.  The annual rent will remain the same throughout the remainder of the extended lease term.  As part of the agreement, the Partnership paid a tenant improvement allowance of $46,750 that was capitalized and will be depreciated.

(4)  Payable to AEI Fund Management, Inc. –

AEI Fund Management, Inc. performs the administrative and operating functions for the Partnership.  The payable to AEI Fund Management represents the balance due for those services.  This balance is non-interest bearing and unsecured and is to be paid in the normal course of business.

(5)  Partners' Capital –

For the nine months ended September 30, 2017 and 2016, the Partnership declared distributions of $730,702 and $786,569, respectively. The Limited Partners received distributions of $723,395 and $778,703 and the General Partners received distributions of $7,307 and $7,866 for the periods, respectively.  The Limited Partners' distributions represented $36.87 and $39.07 per Limited Partnership Unit outstanding using 19,622 and 19,929 weighted average Units in 2017 and 2016, respectively.  The distributions represented $2.41 and $17.87 per Unit of Net Income and $34.46 and $21.20 per Unit of return of contributed capital in 2017 and 2016, respectively.

As part of the distributions discussed above, the Partnership distributed net sale proceeds (from property sales completed in 2014) of $68,812 in 2017.  The Limited Partners received distributions of $68,124 and the General Partners received distributions of $688.  The Limited Partners' distributions represented $3.47 per Unit.

On April 1, 2017, the Partnership repurchased a total of 20.00 Units for $17,616 from one Limited Partner in accordance with the Partnership Agreement.  The Partnership acquired these Units using Net Cash Flow from operations.  On April 1, 2016, the Partnership repurchased a total of 264.01 Units for $233,076 from 12 Limited Partners. The Partnership acquired these Units using net sale proceeds.  The repurchases increase the remaining Limited Partners' ownership interest in the Partnership.  As a result of these repurchases and pursuant to the Partnership Agreement, the General Partners received distributions of $178 and $2,355 in 2017 and 2016, respectively.

(6)  Fair Value Measurements –

As of September 30, 2017 and December 31, 2016, the Partnership had no assets or liabilities measured at fair value on a recurring basis or nonrecurring basis.

Page 10 of 18

ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL

CONDITION AND RESULTS OF OPERATIONS.

This section contains "forward-looking statements" which represent management's expectations or beliefs concerning future events, including statements regarding anticipated application of cash, expected returns from rental income, growth in revenue, the sufficiency of cash to meet operating expenses, rates of distribution, and other matters.  These, and other forward-looking statements, should be evaluated in the context of a number of factors that may affect the Partnership's financial condition and results of operations, including the following:

— Market and economic conditions which affect the value of the properties the Partnership owns and the cash from rental income such properties generate;

— the federal income tax consequences of rental income, deductions, gain on sales and other items and the effects of these consequences for the Partners;

— resolution by the General Partners of conflicts with which they may be confronted;

— the success of the General Partners of locating properties with favorable risk return characteristics;

— the effect of tenant defaults; and

— the condition of the industries in which the tenants of properties owned by the Partnership operate.

Application of Critical Accounting Policies

The Partnership's financial statements have been prepared in accordance with US GAAP.  Preparing the financial statements requires management to use judgment in the application of these accounting policies, including making estimates and assumptions.  These judgments will affect the reported amounts of the Partnership's assets and liabilities and the disclosure of contingent assets and liabilities as of the dates of the financial statements and will affect the reported amounts of revenue and expenses during the reporting periods.  It is possible that the carrying amount of the Partnership's assets and liabilities, or the results of reported operations, will be affected if management's estimates or assumptions prove inaccurate.

Management of the Partnership evaluates the following accounting estimates on an ongoing basis, and has discussed the development and selection of these estimates and the management discussion and analysis disclosures regarding them with the managing partner of the Partnership.

Allocation of Purchase Price of Acquired Properties

Upon acquisition of real properties, the Partnership records them in the financial statements at cost.  The purchase price is allocated to tangible assets, consisting of land and building, and to identified intangible assets and liabilities, which may include the value of above market and below market leases and the value of in-place leases.  The allocation of the purchase price is based upon the fair value of each component of the property.  Although independent appraisals may be used to assist in the determination of fair value, in many cases these values will be based upon management's assessment of each property, the selling prices of comparable properties and the discounted value of cash flows from the asset.

Page 11 of 18

ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS.  (Continued)

The fair values of above market and below market in-place leases will be recorded based on the present value (using an interest rate which reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to the in-place leases and (ii) an estimate of fair market lease rates for the corresponding in-place leases measured over a period equal to the non-cancelable term of the lease including any bargain renewal periods.  The above market and below market lease values will be capitalized as intangible lease assets or liabilities.  Above market lease values will be amortized as an adjustment of rental income over the remaining term of the respective leases.  Below market lease values will be amortized as an adjustment of rental income over the remaining term of the respective leases, including any bargain renewal periods.  If a lease were to be terminated prior to its stated expiration, all unamortized amounts of above market and below market in-place lease values relating to that lease would be recorded as an adjustment to rental income.

The fair values of in-place leases will include estimated direct costs associated with obtaining a new tenant, and opportunity costs associated with lost rentals which are avoided by acquiring an in-place lease.  Direct costs associated with obtaining a new tenant may include commissions, tenant improvements, and other direct costs and are estimated, in part, by management's consideration of current market costs to execute a similar lease.  These direct costs will be included in intangible lease assets on the balance sheet and will be amortized to expense over the remaining term of the respective leases.  The value of opportunity costs will be calculated using the contractual amounts to be paid pursuant to the in-place leases over a market absorption period for a similar lease.  These intangibles will be included in intangible lease assets on the balance sheet and will be amortized to expense over the remaining term of the respective leases.  If a lease were to be terminated prior to its stated expiration, all unamortized amounts of in-place lease assets relating to that lease would be expensed.

The determination of the fair values of the assets and liabilities acquired will require the use of significant assumptions with regard to the current market rental rates, rental growth rates, discount and capitalization rates, interest rates and other variables.  If management's estimates or assumptions prove inaccurate, the result would be an inaccurate allocation of purchase price, which could impact the amount of reported net income.

Carrying Value of Properties

Properties are carried at original cost, less accumulated depreciation and amortization.  The Partnership tests long-lived assets for recoverability when events or changes in circumstances indicate that the carrying value may not be recoverable.  For properties the Partnership will hold and operate, management determines whether impairment has occurred by comparing the property's probability-weighted future undiscounted cash flows to its current carrying value.  For properties held for sale, management determines whether impairment has occurred by comparing the property's estimated fair value less cost to sell to its current carrying value.  If the carrying value is greater than the net realizable value, an impairment loss is recorded to reduce the carrying value of the property to its net realizable value.  Changes in these assumptions or analysis may cause material changes in the carrying value of the properties.

Page 12 of 18

ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS.  (Continued)

Allocation of Expenses

AEI Fund Management, Inc. allocates expenses to each of the funds they manage primarily on the basis of the number of hours devoted by their employees to each fund's affairs.  They also allocate expenses at the end of each month that are not directly related to a fund's operations based upon the number of investors in the fund and the fund's capitalization relative to other funds they manage.  The Partnership reimburses these expenses subject to detailed limitations contained in the Partnership Agreement.

Results of Operations

For the nine months ended September 30, 2017 and 2016, the Partnership recognized rental income of $924,167 and $971,456, respectively.  In 2017, rental income decreased due to the tenant of the KinderCare daycare center receiving free rent, and the Gander Mountain situation, as discussed below.  These decreases were partially offset by additional rent received from one property acquisition in 2016 and rent increases on two properties.  Based on the scheduled rent for the properties as of October 31, 2017, the Partnership expects to recognize rental income of approximately $1,216,000 and $1,182,000 in 2017 and 2018, respectively.

For the nine months ended September 30, 2017 and 2016, the Partnership incurred Partnership administration expenses from affiliated parties of $128,126 and $127,367, respectively.  These administration expenses include costs associated with the management of the properties, processing distributions, reporting requirements and communicating with the Limited Partners.  During the same periods, the Partnership incurred Partnership administration and property management expenses from unrelated parties of $88,753 and $40,075, respectively.  These expenses represent direct payments to third parties for legal and filing fees, direct administrative costs, outside audit costs, taxes, insurance and other property costs.  These expenses were higher in 2017, when compared to 2016, due to expenses related to the Gander Mountain store.

For the nine months ended September 30, 2016, the Partnership incurred property acquisition expenses of $56,760 related to the purchase of the Dollar Tree store in Cincinnati, Ohio.

The Partnership owns a 30% interest in the Gander Mountain store in Champaign, Illinois.  The remaining interests in the property are owned by affiliates of the Partnership.  On March 10, 2017, Gander Mountain Company filed for Chapter 11 reorganization and announced it was closing the store, following a liquidation sale of its on‑site assets.  In June 2017, the tenant filed a motion with the bankruptcy court to reject the lease for this store effective June 30, 2017.  At this time, the tenant returned possession of the property to the owners and the Partnership became responsible for its 30% share of real estate taxes and other costs associated with maintaining the property.  The tenant paid rent through June 2017.  The owners have listed the property for lease with a real estate broker in the Champaign area.  The annual rent from this property represented approximately 13% of the total annual rent of the Partnership's property portfolio.  The loss of rent and increased expenses related to this property decreased the Partnership's cash flow.  Consequently, beginning with the third quarter of 2017, the Partnership reduced its regular quarterly cash distribution rate from $13.18 per Unit to $10.51 per Unit.

Page 13 of 18

ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS.  (Continued)

As a result of the bankruptcy court terminating the lease for the Gander Mountain store, the Partnership included an additional $270,097 in Depreciation and Amortization in the second quarter of 2017, which represented the unamortized balance of the in-place lease intangible that was created when the property was purchased in 2014.

In March 2017, the Partnership entered into an agreement with the tenant of the KinderCare daycare center in Andover, Minnesota to extend the lease term five years to expire on June 30, 2022.  The annual rent will remain the same throughout the remainder of the extended lease term.  As part of the agreement, the Partnership paid a tenant improvement allowance of $30,000 that was capitalized.  In addition, beginning on April 1, 2017, the tenant received free rent for three months that equaled $36,362.  In the first quarter of 2017, the Partnership decided to sell the property.  At September 30, 2017, the property was classified as Real Estate Held for Sale with a carrying value of $652,572.

In October 2017, the Partnership entered into an agreement to sell the KinderCare to an unrelated third party.  The sale is subject to contingencies and may not be completed.  If the sale is completed, the Partnership expects to receive net proceeds of approximately $1,695,000, which will result in a net gain of approximately $1,042,400.

For the nine months ended September 30, 2017 and 2016, the Partnership recognized interest income of $1,097 and $2,361, respectively.

Management believes inflation has not significantly affected income from operations.  Leases may contain rent increases, based on the increase in the Consumer Price Index over a specified period, which will result in an increase in rental income over the term of the leases.  Inflation also may cause the real estate to appreciate in value.  However, inflation and changing prices may have an adverse impact on the operating margins of the properties' tenants, which could impair their ability to pay rent and subsequently reduce the Net Cash Flow available for distributions.

Liquidity and Capital Resources

During the nine months ended September 30, 2017, the Partnership's cash balances decreased $188,630 as a result of cash paid for tenant improvement allowances, and distributions paid to the Partners and cash used to repurchase Units in excess of cash generated from operating activities.  During the nine months ended September 30, 2016, the Partnership's cash balances decreased $2,068,977 as a result of cash used to purchase property, and distributions paid to the Partners and cash used to repurchase Units in excess of cash generated from operating activities.

Net cash provided by operating activities decreased from $765,870 in 2016 to $689,546 in 2017 as a result of a decrease in total rental and interest income in 2017, an increase in Partnership administration and property management expenses in 2017 and net timing differences in the collection of payments from the tenants and the payment of expenses.  During 2016, cash from operations was reduced by $56,760 of acquisition expenses related to the purchase of real estate.  Pursuant to accounting guidance, these expenses were reflected as operating cash outflows.  However, pursuant to the Partnership Agreement, acquisition expenses were funded with proceeds from property sales.

Page 14 of 18

ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS.  (Continued)

The major components of the Partnership's cash flow from investing activities are investments in real estate and proceeds from the sale of real estate.  During the nine months ended September 30, 2017 and 2016, the Partnership expended $76,750 and $1,809,915, respectively, to invest in real properties as the Partnership reinvested cash generated from property sales completed in 2014.

On February 3, 2016, the Partnership purchased a Dollar Tree store in Cincinnati, Ohio for $1,809,915.  The property is leased to Dollar Tree Stores, Inc. under a lease agreement with a remaining primary term of 10 years (as of the date of purchase) and annual rent of $122,169.

In April 2017, the Partnership entered into an agreement with the tenant of the Fresenius Medical Center in Shreveport, Louisiana to extend the lease term nine years to expire on June 30, 2027.  The annual rent will remain the same throughout the remainder of the extended lease term.  As part of the agreement, the Partnership paid a tenant improvement allowance of $46,750 that was capitalized and will be depreciated.

The Partnership's primary use of cash flow, other than investment in real estate, is distribution payments to Partners and cash used to repurchase Units.  The Partnership declares its regular quarterly distributions before the end of each quarter and pays the distribution in the first week after the end of each quarter.  The Partnership attempts to maintain a stable distribution rate from quarter to quarter.  The Partnership may repurchase tendered Units on April 1st and October 1st of each year subject to limitations.

For the nine months ended September 30, 2017 and 2016, the Partnership declared distributions of $730,702 and $786,569, respectively, which were distributed 99% to the Limited Partners and 1% to the General Partners.  The Limited Partners received distributions of $723,395 and $778,703 and the General Partners received distributions of $7,307 and $7,866 for the periods, respectively.

As part of the distributions discussed above, the Partnership distributed net sale proceeds (from property sales completed in 2014) of $68,812 in 2017.  The Limited Partners received distributions of $68,124 and the General Partners received distributions of $688.  The Limited Partners' distributions represented $3.47 per Unit.

The Partnership may repurchase Units from Limited Partners who have tendered their Units to the Partnership.  Such Units may be acquired at a discount.  The Partnership will not be obligated to purchase in any year more than 5% of the total number of Units outstanding on January 1 of such year.  In no event shall the Partnership be obligated to purchase Units if, in the sole discretion of the Managing General Partner, such purchase would impair the capital or operation of the Partnership.

Page 15 of 18

ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS.  (Continued)

On April 1, 2017, the Partnership repurchased a total of 20.00 Units for $17,616 from one Limited Partner in accordance with the Partnership Agreement.  The Partnership acquired these Units using Net Cash Flow from operations.  On April 1, 2016, the Partnership repurchased a total of 264.01 Units for $233,076 from 12 Limited Partners. The Partnership acquired these Units using net sale proceeds.  The repurchases increase the remaining Limited Partners' ownership interest in the Partnership.  As a result of these repurchases and pursuant to the Partnership Agreement, the General Partners received distributions of $178 and $2,355 in 2017 and 2016, respectively.

The continuing rent payments from the properties, together with cash generated from property sales, should be adequate to fund continuing distributions and meet other Partnership obligations on both a short-term and long-term basis.

Off-Balance Sheet Arrangements

As of September 30, 2017 and December 31, 2016, the Partnership had no material off-balance sheet arrangements that had or are reasonably likely to have current or future effects on its financial condition, results of operations, liquidity or capital resources.

ITEM 3.  QUANTITATIVE & QUALITATIVE DISCLOSURES ABOUT MARKET RISK.

Not required for a smaller reporting company.

ITEM 4.  CONTROLS AND PROCEDURES.

(a)  Disclosure Controls and Procedures.

Under the supervision and with the participation of management, including its President and Chief Financial Officer, the Managing General Partner of the Partnership evaluated the effectiveness of the design and operation of our disclosure controls and procedures (as defined in Rule 13a-15(e) under the Securities Exchange Act of 1934 (the "Exchange Act")).  Based upon that evaluation, the President and Chief Financial Officer of the Managing General Partner concluded that, as of the end of the period covered by this report, our disclosure controls and procedures were effective in ensuring that information required to be disclosed by us in the reports that we file or submit under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in applicable rules and forms and that such information is accumulated and communicated to management, including the President and Chief Financial Officer of the Managing General Partner, in a manner that allows timely decisions regarding required disclosure.

(b)  Changes in Internal Control Over Financial Reporting.

During the most recent period covered by this report, there has been no change in our internal control over financial reporting (as defined in Rule 13a-15(f) under the Exchange Act) that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

Page 16 of 18

PART II – OTHER INFORMATION

ITEM 1.  LEGAL PROCEEDINGS.

There are no material pending legal proceedings to which the Partnership is a party or of which the Partnership's property is subject.

ITEM 1A.  RISK FACTORS.

Not required for a smaller reporting company.

ITEM 2.  UNREGISTERED SALES OF EQUITY SECURITIES & USE OF PROCEEDS.

(a) None.

(b) Not applicable.

(c) Pursuant to Section 7.7 of the Partnership Agreement, as amended, each Limited Partner has the right to present Units to the Partnership for purchase by submitting notice to the Managing General Partner during January or July of each year.  The purchase price of the Units is equal to 95% of the net asset value per Unit, as of the first business day of January or July of each year, as determined by the Managing General Partner in accordance with the provisions of the Partnership Agreement.  Units tendered to the Partnership during January and July may be repurchased on April 1^st and October 1^st, respectively, of each year subject to the following limitations.  The Partnership will not be obligated to purchase in any year more than 5% of the total number of Units outstanding on January 1 of such year.  In no event shall the Partnership be obligated to purchase Units if, in the sole discretion of the Managing General Partner, such purchase would impair the capital or operation of the Partnership.  During the period covered by this report, the Partnership did not purchase any Units.

ITEM 3.  DEFAULTS UPON SENIOR SECURITIES.

None.

ITEM 4.  MINE SAFETY DISCLOSURES.

Not Applicable.

ITEM 5.  OTHER INFORMATION.

None.

Page 17 of 18

ITEM 6.  EXHIBITS.

31.1 Certification of Chief Executive Officer of General Partner pursuant to Rule 15d-14(a)(17 CFR 240.15d-14(a)) and Section 302 of the Sarbanes-Oxley Act of 2002.

31.2 Certification of Chief Financial Officer of General Partner pursuant to Rule 15d-14(a)(17 CFR 240.15d-14(a)) and Section 302 of the Sarbanes-Oxley Act of 2002.

32 Certification of Chief Executive Officer and Chief Financial Officer of General Partner pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

Dated:  November 13, 2017	AEI Income & Growth Fund XXI
	Limited Partnership
	By:	AEI Fund Management XXI, Inc.
	Its:	Managing General Partner
	By:	/s/ ROBERT P JOHNSON
		Robert P. Johnson
		President
		(Principal Executive Officer)
	By:	/s/ PATRICK W KEENE
		Patrick W. Keene
		Chief Financial Officer
		(Principal Accounting Officer)

Page 18 of 18

EX-31.1

Exhibit 31.1

CERTIFICATIONS

I, Robert P. Johnson, certify that:

1. I have reviewed this quarterly report on Form 10-Q of AEI Income & Growth Fund XXI Limited Partnership;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a)Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b)Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c)Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d)Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

5. The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

a)All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

b)Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

Date:  November 13, 2017	/s/ ROBERT P JOHNSON
	Robert P. Johnson, President
	AEI Fund Management XXI, Inc.
	Managing General Partner

EX-31.2

Exhibit 31.2

CERTIFICATIONS

I, Patrick W. Keene, certify that:

1. I have reviewed this quarterly report on Form 10-Q of AEI Income & Growth Fund XXI Limited Partnership;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a)Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b)Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c)Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d)Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

5. The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

a)All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

b)Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

Date:  November 13, 2017	/s/ PATRICK W KEENE
	Patrick W. Keene, Chief Financial Officer
	AEI Fund Management XXI, Inc.
	Managing General Partner

EX-32

Exhibit 32

CERTIFICATION PURSUANT TO

18 U.S.C. §1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of AEI Income & Growth Fund XXI Limited Partnership (the "Partnership") on Form 10-Q for the period ended September 30, 2017, as filed with the Securities and Exchange Commission on the date hereof (the "Report"), the undersigned, Robert P. Johnson, President of AEI Fund Management XXI, Inc., the Managing General Partner of the Partnership, and Patrick W. Keene, Chief Financial Officer of AEI Fund Management XXI, Inc., each certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

1. The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Partnership.

 /s/ ROBERT P JOHNSON

Robert P. Johnson, President

AEI Fund Management XXI, Inc.

Managing General Partner

November 13, 2017

 /s/ PATRICK W KEENE

Patrick W. Keene, Chief Financial Officer

AEI Fund Management XXI, Inc.

Managing General Partner

November 13, 2017

XML

Document And Entity Information	9 Months Ended
	Sep. 30, 2017 USD ($) shares
Document and Entity Information [Abstract]
Entity Registrant Name	AEI Income & Growth Fund XXI Ltd Partnership
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding | shares	19,616
Entity Public Float | $	$ 0
Amendment Flag	false
Entity Central Index Key	0000931755
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Smaller Reporting Company
Entity Well-known Seasoned Issuer	No
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3

XML

Balance Sheet - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Current Assets:
Cash	$ 502,495	$ 691,125
Real Estate Investments:
Land	3,659,461	3,839,216
Buildings	10,339,539	11,377,241
Acquired Intangible Lease Assets	807,178	807,178
Real Estate Held for Investment, at cost	14,806,178	16,023,635
Accumulated Depreciation and Amortization	(3,651,584)	(3,650,418)
Real Estate Held for Investment, Net	11,154,594	12,373,217
Real Estate Held for Sale	652,572	0
Total Real Estate Investments	11,807,166	12,373,217
Total Assets	12,309,661	13,064,342
Current Liabilities:
Payable to AEI Fund Management, Inc.	238	27,151
Distributions Payable	208,282	261,212
Unearned Rent	34,520	12,121
Total Current Liabilities	243,040	300,484
Long-term Liabilities:
Acquired Below-Market Lease Intangibles, Net	111,530	125,855
Partners’ Capital (Deficit):
General Partners	(25,382)	(18,553)
Limited Partners – 24,000 Units authorized; 19,616 and 19,636 Units issued and outstanding as of 9/30/17 and 12/31/16, respectively	11,980,473	12,656,556
Total Partners' Capital	11,955,091	12,638,003
Total Liabilities and Partners' Capital	12,309,661	13,064,342
Limited Partner [Member]
Partners’ Capital (Deficit):
Total Partners' Capital	$ 11,980,473	$ 12,656,556

XML

Balance Sheet (Parentheticals) - Limited Partner [Member] - shares	Sep. 30, 2017	Dec. 31, 2016
Limited Partners, units authorized	24,000	24,000
Limited Partners, units issued	19,616	19,636
Limited Partners, units outstanding	19,616	19,636

XML

Statement of Income - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Rental Income	$ 292,215	$ 328,755	$ 924,167	$ 971,456
Expenses:
Partnership Administration – Affiliates	41,384	41,010	128,126	127,367
Partnership Administration and Property Management – Unrelated Parties	51,348	7,891	88,753	40,075
Property Acquisition	0	27	0	56,760
Depreciation and Amortization	117,621	132,964	642,801	389,933
Total Expenses	210,353	181,892	859,680	614,135
Operating Income	81,862	146,863	64,487	357,321
Other Income:
Interest Income	302	549	1,097	2,361
Net Income	82,164	147,412	65,584	359,682
Net Income Allocated:
General Partners	822	1,474	656	3,597
Limited Partners	$ 81,342	$ 145,938	$ 64,928	$ 356,085
Net Income per Limited Partnership Unit (in Dollars per share)	$ 4.15	$ 7.36	$ 3.31	$ 17.87
Weighted Average Units Outstanding – Basic and Diluted (in Shares)	19,616	19,841	19,622	19,929

XML

Statement of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash Flows from Operating Activities:
Net Income	$ 65,584	$ 359,682
Adjustments to Reconcile Net Income To Net Cash Provided by Operating Activities:
Depreciation and Amortization	628,476	376,959
Increase (Decrease) in Payable to AEI Fund Management, Inc.	(26,913)	6,829
Increase (Decrease) in Unearned Rent	22,399	22,400
Total Adjustments	623,962	406,188
Net Cash Provided By (Used For) Operating Activities	689,546	765,870
Cash Flows from Investing Activities:
Investments in Real Estate	(76,750)	(1,809,915)
Cash Flows from Financing Activities:
Distributions Paid to Partners	(783,632)	(789,501)
Repurchase of Partnership Units	(17,794)	(235,431)
Net Cash Provided By (Used For) Financing Activities	(801,426)	(1,024,932)
Net Increase (Decrease) in Cash	(188,630)	(2,068,977)
Cash, beginning of period	691,125	2,925,122
Cash, end of period	$ 502,495	$ 856,145

XML

Statement of Changes in Partners' Capital - USD ($)	General Partner [Member]	Limited Partner [Member]	Total
Balance at Dec. 31, 2015	$ (9,126)	$ 13,589,851	$ 13,580,725
Balance (in Shares) at Dec. 31, 2015		20,104.88
Balance at Sep. 30, 2016	(15,750)	$ 12,934,157	12,918,407
Balance (in Shares) at Sep. 30, 2016		19,840.87
Distributions Declared	(7,866)	$ (778,703)	(786,569)
Repurchase of Partnership Units	(2,355)	$ (233,076)	(235,431)
Units Repurchased (in Shares)		(264.01)
Net Income	3,597	$ 356,085	359,682
Balance at Dec. 31, 2016	(18,553)	$ 12,656,556	12,638,003
Balance (in Shares) at Dec. 31, 2016		19,636
Balance at Sep. 30, 2017	(25,382)	$ 11,980,473	11,955,091
Balance (in Shares) at Sep. 30, 2017		19,616
Distributions Declared	(7,307)	$ (723,395)	(730,702)
Repurchase of Partnership Units	(178)	$ (17,616)	(17,794)
Units Repurchased (in Shares)		(20.00)
Net Income	$ 656	$ 64,928	$ 65,584

XML

Basis of Accounting

9 Months Ended

Sep. 30, 2017

Disclosure Text Block [Abstract]

Basis of Accounting [Text Block]

(1)  The condensed statements included herein have been prepared by the registrant, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission, and reflect all adjustments which are, in the opinion of management, necessary to a fair statement of the results of operations for the interim period, on a basis consistent with the annual audited statements.  The adjustments made to these condensed statements consist only of normal recurring adjustments.  Certain information, accounting policies, and footnote disclosures normally included in financial statements prepared in accordance with United States Generally Accepted Accounting Principles (US GAAP) have been condensed or omitted pursuant to such rules and regulations, although the registrant believes that the disclosures are adequate to make the information presented not misleading.  It is suggested that these condensed financial statements be read in conjunction with the financial statements and the summary of significant accounting policies and notes thereto included in the registrant’s latest annual report on Form 10K.

XML

Organization

9 Months Ended

Sep. 30, 2017

Accounting Policies [Abstract]

Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]

(2)  Organization –

AEI Income & Growth Fund XXI Limited Partnership (“Partnership”) was formed to acquire and lease commercial properties to operating tenants.  The Partnership's operations are managed by AEI Fund Management XXI, Inc. (“AFM”), the Managing General Partner.  Robert P. Johnson, the President and sole director of AFM, serves as the Individual General Partner.  AFM is a wholly owned subsidiary of AEI Capital Corporation of which Mr. Johnson is the majority shareholder.  AEI Fund Management, Inc. (“AEI”), an affiliate of AFM, performs the administrative and operating functions for the Partnership.

The terms of the Partnership offering called for a subscription price of $1,000 per Limited Partnership Unit, payable on acceptance of the offer.  The Partnership commenced operations on April 14, 1995 when minimum subscriptions of 1,500 Limited Partnership Units ($1,500,000) were accepted.  On January 31, 1997, the offering terminated when the maximum subscription limit of 24,000 Limited Partnership Units was reached.  Under the terms of the Limited Partnership Agreement, the Limited Partners and General Partners contributed funds of $24,000,000 and $1,000, respectively.

During operations, any Net Cash Flow, as defined, which the General Partners determine to distribute will be distributed 90% to the Limited Partners and 10% to the General Partners; provided, however, that such distributions to the General Partners will be subordinated to the Limited Partners first receiving an annual, noncumulative distribution of Net Cash Flow equal to 10% of their Adjusted Capital Contribution, as defined, and, provided further, that in no event will the General Partners receive less than 1% of such Net Cash Flow per annum.  Distributions to Limited Partners will be made pro rata by Units.

Any Net Proceeds of Sale, as defined, from the sale or financing of properties which the General Partners determine to distribute will, after provisions for debts and reserves, be paid in the following manner: (i) first, 99% to the Limited Partners and 1% to the General Partners until the Limited Partners receive an amount equal to: (a) their Adjusted Capital Contribution plus (b) an amount equal to 10% of their Adjusted Capital Contribution per annum, cumulative but not compounded, to the extent not previously distributed from Net Cash Flow;  (ii) any remaining balance will be distributed 90% to the Limited Partners and 10% to the General Partners.  Distributions to the Limited Partners will be made pro rata by Units.

For tax purposes, profits from operations, other than profits attributable to the sale, exchange, financing, refinancing or other disposition of property, will be allocated first in the same ratio in which, and to the extent, Net Cash Flow is distributed to the Partners for such year.  Any additional profits will be allocated in the same ratio as the last dollar of Net Cash Flow is distributed.  Net losses from operations will be allocated 99% to the Limited Partners and 1% to the General Partners.

For tax purposes, profits arising from the sale, financing, or other disposition of property will be allocated in accordance with the Partnership Agreement as follows: (i) first, to those partners with deficit balances in their capital accounts in an amount equal to the sum of such deficit balances; (ii) second, 99% to the Limited Partners and 1% to the General Partners until the aggregate balance in the Limited Partners' capital accounts equals the sum of the Limited Partners' Adjusted Capital Contributions plus an amount equal to 10% of their Adjusted Capital Contributions per annum, cumulative but not compounded, to the extent not previously allocated; (iii) third, the balance of any remaining gain will then be allocated 90% to the Limited Partners and 10% to the General Partners.  Losses will be allocated 98% to the Limited Partners and 2% to the General Partners.

The General Partners are not required to currently fund a deficit capital balance.  Upon liquidation of the Partnership or withdrawal by a General Partner, the General Partners will contribute to the Partnership an amount equal to the lesser of the deficit balances in their capital accounts or 1% of total Limited Partners' and General Partners' capital contributions.

In January 2014, the Managing General Partner mailed a Consent Statement (Proxy) seeking the consent of the Limited Partners to continue the Partnership for an additional 60 months or to initiate the final disposition, liquidation and distribution of all of the Partnership’s properties and assets.  On February 14, 2014, the proposal to continue the Partnership was approved with a majority of Units voted in favor of the continuation proposal.  As a result, the Managing General Partner will continue the operations of the Partnership for an additional 60 months at which time it will again ask the Limited Partners to vote on the same two proposals.

XML

Real Estate Investments

9 Months Ended

Sep. 30, 2017

Real Estate [Abstract]

Real Estate Disclosure [Text Block]

(3)  Real Estate Investments –

On February 3, 2016, the Partnership purchased a Dollar Tree store in Cincinnati, Ohio for $1,809,915.  The Partnership allocated $285,049 of the purchase price to Acquired Intangible Lease Assets, representing in-place lease intangibles, and allocated $80,404 to Acquired Below-Market Lease Intangibles. The Partnership incurred $56,760 of acquisition expenses related to the purchase that were expensed.  The property is leased to Dollar Tree Stores, Inc. under a lease agreement with a remaining primary term of 10 years (as of the date of purchase) and annual rent of $122,169.

The Partnership owns a 30% interest in the Gander Mountain store in Champaign, Illinois.  The remaining interests in the property are owned by affiliates of the Partnership.  On March 10, 2017, Gander Mountain Company filed for Chapter 11 reorganization and announced it was closing the store, following a liquidation sale of its onsite assets.  In June 2017, the tenant filed a motion with the bankruptcy court to reject the lease for this store effective June 30, 2017. At this time, the tenant returned possession of the property to the owners and the Partnership became responsible for its 30% share of real estate taxes and other costs associated with maintaining the property. The tenant paid rent through June 2017.  The owners have listed the property for lease with a real estate broker in the Champaign area.  The annual rent from this property represented approximately 13% of the total annual rent of the Partnership's property portfolio.  The loss of rent and increased expenses related to this property decreased the Partnership's cash flow.  Consequently, beginning with the third quarter of 2017, the Partnership reduced its regular quarterly cash distribution rate from $13.18 per Unit to $10.51 per Unit.

As a result of the bankruptcy court terminating the lease for the Gander Mountain store, the Partnership included an additional $270,097 in Depreciation and Amortization in the second quarter of 2017, which represented the unamortized balance of the in-place lease intangible that was created when the property was purchased in 2014.

In March 2017, the Partnership entered into an agreement with the tenant of the KinderCare daycare center in Andover, Minnesota to extend the lease term five years to expire on June 30, 2022.  The annual rent will remain the same throughout the remainder of the extended lease term.  As part of the agreement, the Partnership paid a tenant improvement allowance of $30,000 that was capitalized.  In addition, beginning on April 1, 2017, the tenant received free rent for three months that equaled $36,362.  In the first quarter of 2017, the Partnership decided to sell the property.  At September 30, 2017, the property was classified as Real Estate Held for Sale with a carrying value of $652,572.

In October 2017, the Partnership entered into an agreement to sell the KinderCare to an unrelated third party.  The sale is subject to contingencies and may not be completed.  If the sale is completed, the Partnership expects to receive net proceeds of approximately $1,695,000, which will result in a net gain of approximately $1,042,400.

In April 2017, the Partnership entered into an agreement with the tenant of the Fresenius Medical Center in Shreveport, Louisiana to extend the lease term nine years to expire on June 30, 2027.  The annual rent will remain the same throughout the remainder of the extended lease term.  As part of the agreement, the Partnership paid a tenant improvement allowance of $46,750 that was capitalized and will be depreciated.

XML

Payable to AEI Fund Management, Inc.

9 Months Ended

Sep. 30, 2017

Payables and Accruals [Abstract]

Accounts Payable and Accrued Liabilities Disclosure [Text Block]

(4)  Payable to AEI Fund Management, Inc. –

AEI Fund Management, Inc. performs the administrative and operating functions for the Partnership.  The payable to AEI Fund Management represents the balance due for those services.  This balance is non-interest bearing and unsecured and is to be paid in the normal course of business.

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Partners' Capital

9 Months Ended

Sep. 30, 2017

Partners' Capital Notes [Abstract]

Partners' Capital Notes Disclosure [Text Block]

(5)  Partners’ Capital –

For the nine months ended September 30, 2017 and 2016, the Partnership declared distributions of $730,702 and $786,569, respectively. The Limited Partners received distributions of $723,395 and $778,703 and the General Partners received distributions of $7,307 and $7,866 for the periods, respectively.  The Limited Partners' distributions represented $36.87 and $39.07 per Limited Partnership Unit outstanding using 19,622 and 19,929 weighted average Units in 2017 and 2016, respectively.  The distributions represented $2.41 and $17.87 per Unit of Net Income and $34.46 and $21.20 per Unit of return of contributed capital in 2017 and 2016, respectively.

As part of the distributions discussed above, the Partnership distributed net sale proceeds (from property sales completed in 2014) of $68,812 in 2017.  The Limited Partners received distributions of $68,124 and the General Partners received distributions of $688.  The Limited Partners’ distributions represented $3.47 per Unit.

On April 1, 2017, the Partnership repurchased a total of 20.00 Units for $17,616 from one Limited Partner in accordance with the Partnership Agreement.  The Partnership acquired these Units using Net Cash Flow from operations.  On April 1, 2016, the Partnership repurchased a total of 264.01 Units for $233,076 from 12 Limited Partners. The Partnership acquired these Units using net sale proceeds.  The repurchases increase the remaining Limited Partners' ownership interest in the Partnership.  As a result of these repurchases and pursuant to the Partnership Agreement, the General Partners received distributions of $178 and $2,355 in 2017 and 2016, respectively.

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Fair Value Measurements

9 Months Ended

Sep. 30, 2017

Fair Value Disclosures [Abstract]

Fair Value Disclosures [Text Block]

(6)  Fair Value Measurements –

As of September 30, 2017 and December 31, 2016, the Partnership had no assets or liabilities measured at fair value on a recurring basis or nonrecurring basis.

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Accounting Policies, by Policy (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Distribution Policy, Members or Limited Partners, Description	During operations, any Net Cash Flow, as defined, which the General Partners determine to distribute will be distributed 90% to the Limited Partners and 10% to the General Partners; provided, however, that such distributions to the General Partners will be subordinated to the Limited Partners first receiving an annual, noncumulative distribution of Net Cash Flow equal to 10% of their Adjusted Capital Contribution, as defined, and, provided further, that in no event will the General Partners receive less than 1% of such Net Cash Flow per annum. Distributions to Limited Partners will be made pro rata by Units.Any Net Proceeds of Sale, as defined, from the sale or financing of properties which the General Partners determine to distribute will, after provisions for debts and reserves, be paid in the following manner: (i) first, 99% to the Limited Partners and 1% to the General Partners until the Limited Partners receive an amount equal to: (a) their Adjusted Capital Contribution plus (b) an amount equal to 10% of their Adjusted Capital Contribution per annum, cumulative but not compounded, to the extent not previously distributed from Net Cash Flow; (ii) any remaining balance will be distributed 90% to the Limited Partners and 10% to the General Partners. Distributions to the Limited Partners will be made pro rata by Units.
Key Provisions of Operating or Partnership Agreement, Description	For tax purposes, profits from operations, other than profits attributable to the sale, exchange, financing, refinancing or other disposition of property, will be allocated first in the same ratio in which, and to the extent, Net Cash Flow is distributed to the Partners for such year. Any additional profits will be allocated in the same ratio as the last dollar of Net Cash Flow is distributed. Net losses from operations will be allocated 99% to the Limited Partners and 1% to the General Partners.For tax purposes, profits arising from the sale, financing, or other disposition of property will be allocated in accordance with the Partnership Agreement as follows: (i) first, to those partners with deficit balances in their capital accounts in an amount equal to the sum of such deficit balances; (ii) second, 99% to the Limited Partners and 1% to the General Partners until the aggregate balance in the Limited Partners' capital accounts equals the sum of the Limited Partners' Adjusted Capital Contributions plus an amount equal to 10% of their Adjusted Capital Contributions per annum, cumulative but not compounded, to the extent not previously allocated; (iii) third, the balance of any remaining gain will then be allocated 90% to the Limited Partners and 10% to the General Partners. Losses will be allocated 98% to the Limited Partners and 2% to the General Partners.The General Partners are not required to currently fund a deficit capital balance. Upon liquidation of the Partnership or withdrawal by a General Partner, the General Partners will contribute to the Partnership an amount equal to the lesser of the deficit balances in their capital accounts or 1% of total Limited Partners' and General Partners' capital contributions.

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Organization (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015	Jan. 31, 1997	Apr. 14, 1995
Limited Partner [Member]
Organization (Details) [Line Items]
Capital Units, Value						$ 1,000
Limited Partners' Capital Account, Units Outstanding (in Shares)	19,616	19,636	19,840.87	20,104.88	24,000	1,500
Limited Partners' Contributed Capital					$ 24,000,000	$ 1,500,000
General Partner [Member]
Organization (Details) [Line Items]
General Partners' Contributed Capital					$ 1,000

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Real Estate Investments (Details) - USD ($)				3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
	Apr. 01, 2017	Mar. 01, 2017	Feb. 03, 2016	Sep. 30, 2017	Jun. 30, 2017	Jun. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Feb. 03, 2017	Apr. 01, 2015
Real Estate Investments (Details) [Line Items]
Payments to Acquire Real Estate							$ 76,750	$ 1,809,915
Distributions Per Limited Partnership Unit Outstanding, Basic (in Dollars per share)				$ 10.51		$ 13.18
Gander Mountain Champaign IL Member
Real Estate Investments (Details) [Line Items]
Amortization of Intangible Assets					$ 270,097
Fresenius Shreveport LA
Real Estate Investments (Details) [Line Items]
Payments for Tenant Improvements	$ 46,750
Dollar Tree Cincinnatio OH
Real Estate Investments (Details) [Line Items]
Payments to Acquire Real Estate			$ 1,809,915
Business Acquisition, Transaction Costs			56,760
Real Estate Revenue, Net									$ 122,169
Dollar Tree Cincinnatio OH | Leases, Acquired-in-Place [Member]
Real Estate Investments (Details) [Line Items]
Finite-Lived Intangible Asset, Acquired-in-Place Leases			285,049
Dollar Tree Cincinnatio OH | Off Market Unfavorable Lease Member
Real Estate Investments (Details) [Line Items]
Below Market Lease, Acquired			$ 80,404
KinderCare Andover MN
Real Estate Investments (Details) [Line Items]
Payments for Tenant Improvements		$ 30,000
Allowance for Notes, Loans and Financing Receivable, Current										$ 36,362
Property, Plant, and Equipment, Fair Value Disclosure				$ 652,572			$ 652,572

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Partners' Capital (Details)	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2017 $ / shares shares	Sep. 30, 2016 shares	Jun. 30, 2017 $ / shares	Sep. 30, 2017 USD ($) $ / shares $ / item shares	Sep. 30, 2016 USD ($) $ / shares $ / item shares
Partners' Capital (Details) [Line Items]
Partners' Capital Account, Distributions				$ 730,702	$ 786,569
Distributions Per Limited Partnership Unit Outstanding, Basic (in Dollars per share) | $ / shares	$ 10.51		$ 13.18
Weighted Average Limited Partnership Units Outstanding, Basic (in Shares) | shares	19,616	19,841		19,622	19,929
Sale Proceeds Distribution Made to Member or Limited Partner				$ 68,812
Partners' Capital Account, Redemptions				17,794	$ 235,431
Limited Partner [Member]
Partners' Capital (Details) [Line Items]
Partners' Capital Account, Distributions				$ 723,395	$ 778,703
Distributions Per Limited Partnership Unit Outstanding, Basic (in Dollars per share) | $ / shares				$ 36.87	$ 39.07
Weighted Average Limited Partnership Units Outstanding, Basic (in Shares) | shares				19,622	19,929
Distributions Per Unit of Net Income (in Dollars per Item) | $ / item				2.41	17.87
Distributions Per Unit of Return of Capital (in Dollars per Item) | $ / item				34.46	21.20
Sale Proceeds Distribution Made to Member or Limited Partner				$ 68,124
Sale Proceeds Distribution Made to Limited Partner Per Unit				$ 3.47
Partners' Capital Account, Units, Redeemed (in Shares) | shares				20.00	264.01
Partners' Capital Account, Redemptions				$ 17,616	$ 233,076
General Partner [Member]
Partners' Capital (Details) [Line Items]
Partners' Capital Account, Distributions				7,307	7,866
Sale Proceeds Distribution Made to Member or Limited Partner				688
Partners' Capital Account, Redemptions				$ 178	$ 2,355