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, 2013

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.     x Yes    o 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).     x Yes    o 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.

o Large accelerated filer	o Accelerated filer
o Non-accelerated filer	x Smaller reporting company

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

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

INDEX

				Page
Part I – Financial Information
	Item 1.	Financial Statements (unaudited):
		Balance Sheet as of September 30, 2013 and December 31, 2012		3
		Statements for the Periods ended September 30, 2013 and 2012:
			Income	4
			Cash Flows	5
			Changes in Partners’ Capital	6
		Notes to Financial Statements		7 - 10
	Item 2.	Management's Discussion and Analysis of Financial
			Condition and Results of Operations	10 - 14
	Item 3.	Quantitative and Qualitative Disclosures About Market Risk		14
	Item 4.	Controls and Procedures		14
Part II – Other Information
	Item 1.	Legal Proceedings		14
	Item 1A.	Risk Factors		14
	Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds		15
	Item 3.	Defaults Upon Senior Securities		15
	Item 4.	Mine Safety Disclosures		15
	Item 5.	Other Information		15
	Item 6.	Exhibits		15
Signatures				16

Page 2 of 16

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

BALANCE SHEET

ASSETS

		September 30,		December 31,
		2013		2012
Current Assets:
Cash	$	6,061,006	$	2,259,911
Real Estate Held for Investment:
Land		3,681,363		4,403,667
Buildings and Equipment		9,879,315		12,273,366
Accumulated Depreciation		(2,811,196)		(2,930,639)
Real Estate Held for Investment, Net		10,749,482		13,746,394
Total Assets	$	16,810,488	$	16,006,305

LIABILITIES AND PARTNERS' CAPITAL

Current Liabilities:
Payable to AEI Fund Management, Inc.	$	126,744	$	41,189
Distributions Payable		594,952		293,940
Unearned Rent		33,331		12,120
Total Current Liabilities		755,027		347,249
Partners’ Capital:
General Partners		11,221		686
Limited Partners – 24,000 Units authorized;    22,653 Units issued and outstanding		16,044,240		15,658,370
Total Partners' Capital		16,055,461		15,659,056
Total Liabilities and Partners' Capital	$	16,810,488	$	16,006,305

The accompanying Notes to Financial Statements are an integral part of this statement.

Page 3 of 16

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

STATEMENT OF INCOME

		Three Months Ended September 30				Nine Months Ended September 30
		2013		2012		2013		2012
Rental Income	$	278,308	$	272,545	$	829,686	$	811,024
Expenses:
Partnership Administration – Affiliates		50,650		53,588		152,129		163,845
Partnership Administration and Property    Management – Unrelated Parties		17,181		7,148		42,398		34,794
Depreciation		98,794		98,794		296,382		296,382
Total Expenses		166,625		159,530		490,909		495,021
Operating Income		111,683		113,015		338,777		316,003
Other Income:
Interest Income		3,126		1,859		6,277		6,085
Income from Continuing Operations		114,809		114,874		345,054		322,088
Income from Discontinued Operations		1,157,138		64,707		1,234,181		181,357
Net Income	$	1,271,947	$	179,581	$	1,579,235	$	503,445
Net Income Allocated:
General Partners	$	19,290	$	1,795	$	22,363	$	5,034
Limited Partners		1,252,657		177,786		1,556,872		498,411
Total	$	1,271,947	$	179,581	$	1,579,235	$	503,445
Income per Limited Partnership Unit:
Continuing Operations	$	5.02	$	5.02	$	15.08	$	14.07
Discontinued Operations		50.28		2.82		53.65		7.92
Total – Basic and Diluted	$	55.30	$	7.84	$	68.73	$	21.99
Weighted Average Units Outstanding –       Basic and Diluted		22,653		22,663		22,653		22,663

The accompanying Notes to Financial Statements are an integral part of this statement.

Page 4 of 16

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

STATEMENT OF CASH FLOWS

		Nine Months Ended September 30
		2013		2012
Cash Flows from Operating Activities:
Net Income	$	1,579,235	$	503,445
Adjustments to Reconcile Net Income To Net Cash Provided by Operating Activities:
Depreciation		344,262		368,202
Gain on Sale of Real Estate		(1,128,749)		(46,795)
Increase (Decrease) in Payable to    AEI Fund Management, Inc.		85,555		(2,434)
Increase (Decrease) in Unearned Rent		21,211		2,044
Total Adjustments		(677,721)		321,017
Net Cash Provided By    Operating Activities		901,514		824,462
Cash Flows from Investing Activities:
Proceeds from Sale of Real Estate		3,781,399		277,275
Cash Flows from Financing Activities:
Distributions Paid to Partners		(881,818)		(881,806)
Net Increase (Decrease) in Cash		3,801,095		219,931
Cash, beginning of period		2,259,911		1,934,854
Cash, end of period	$	6,061,006	$	2,154,785

The accompanying Notes to Financial Statements are an integral part of this statement.

Page 5 of 16

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

STATEMENT OF CHANGES IN PARTNERS' CAPITAL

		General Partners		Limited Partners		Total	Limited Partnership Units Outstanding
Balance, December 31, 2011	$	4,646	$	16,170,124	$	16,174,770	22,663.11
Distributions Declared		(8,818)		(872,988)		(881,806)
Net Income		5,034		498,411		503,445
Balance, September 30, 2012	$	862	$	15,795,547	$	15,796,409	22,663.11
Balance, December 31, 2012	$	686	$	15,658,370	$	15,659,056	22,653.11
Distributions Declared		(11,828)		(1,171,002)		(1,182,830)
Net Income		22,363		1,556,872		1,579,235
Balance, September 30, 2013	$	11,221	$	16,044,240	$	16,055,461	22,653.11

The accompanying Notes to Financial Statements are an integral part of this statement.

Page 6 of 16

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

NOTES TO FINANCIAL STATEMENTS

SEPTEMBER 30, 2013

(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 generally accepted accounting principles 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 16

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.

(3)  Reclassification –

Certain items related to discontinued operations in the prior year’s financial statements have been reclassified to conform to 2013 presentation.  These reclassifications had no effect on Partners’ capital, net income or cash flows.

(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.

Page 8 of 16

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

NOTES TO FINANCIAL STATEMENTS

(Continued)

(5)  Discontinued Operations –

On February 3, 2012, the Partnership sold its remaining 2.6811% interest in the Arby’s restaurant in Montgomery, Alabama to an unrelated third party.  The Partnership received net sale proceeds of $16,200, which resulted in a net gain of $1,788.  The cost and related accumulated depreciation of the interest sold was $23,049 and $8,637, respectively.

During 2012, the Partnership sold its remaining 8.8038% interest in the Winn-Dixie store in Panama City, Florida, in three separate transactions, to unrelated third parties.  The Partnership received total net sale proceeds of $406,884, which resulted in a net gain of $68,108.  The cost and related accumulated depreciation of the interests sold was $408,060 and $69,284, respectively.  For the nine months ended September 30, 2012, the net gain was $45,007.

On August 2, 2013, the Partnership sold its 39% interest in the Scott & White Clinic in College Station, Texas to an unrelated third party.  The Partnership received net sale proceeds of $1,822,494, which resulted in a net gain of $512,842.  At the time of sale, the cost and related accumulated depreciation was $1,433,468 and $123,816, respectively.

In June 2013, the Partnership entered into an agreement to sell its 62% interest in the Applebee’s restaurant in Johnstown, Pennsylvania to an unrelated third party.  On August 23, 2013, the sale closed with the Partnership receiving net sale proceeds of $1,958,905, which resulted in a net gain of $615,907.  At the time of sale, the cost and related accumulated depreciation was $1,682,887 and $339,889, respectively.

During the first nine months of 2013 and 2012, the Partnership distributed net sale proceeds of $388,083 and $56,955 to the Limited and General Partners as part of their quarterly distributions, which represented a return of capital of $16.96 and $2.49 per Limited Partnership Unit, respectively.

The financial results for these properties are reflected as Discontinued Operations in the accompanying financial statements.  The following are the results of discontinued operations:

		Three Months Ended September 30				Nine Months Ended September 30
		2013		2012		2013		2012
Rental Income	$	28,567	$	66,271	$	153,847	$	208,021
Property Management Expenses		(178)		(943)		(535)		(1,639)
Depreciation		0		(23,940)		(47,880)		(71,820)
Gain on Disposal of Real Estate		1,128,749		23,319		1,128,749		46,795
Income from Discontinued Operations	$	1,157,138	$	64,707	$	1,234,181	$	181,357

Page 9 of 16

AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP

NOTES TO FINANCIAL STATEMENTS

(Continued)

(7)  Fair Value Measurements –

As of September 30, 2013, the Partnership had no assets or liabilities measured at fair value on a recurring basis or nonrecurring basis.

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 preparation of the Partnership’s financial statements requires management to make estimates and assumptions that may affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. Management evaluates these estimates on an ongoing basis, including those related to the carrying value of investments in real estate and the allocation by AEI Fund Management, Inc. of expenses to the Partnership as opposed to other funds they manage.

The Partnership purchases properties and records them in the financial statements at cost (not including acquisition expenses).  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 10 of 16

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

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.

Management of the Partnership has discussed the development and selection of the above accounting estimates and the management discussion and analysis disclosures regarding them with the managing partner of the Partnership.

Results of Operations

For the nine months ended September 30, 2013 and 2012, the Partnership recognized rental income from continuing operations of $829,686 and $811,024, respectively.  In 2013, rental income increased due to additional rent received from rent increases on three properties.  Based on the scheduled rent for the properties owned as of October 31, 2013, the Partnership expects to recognize rental income from continuing operations of approximately $1,107,000 and $1,116,000 in 2013 and 2014, respectively.

For the nine months ended September 30, 2013 and 2012, the Partnership incurred Partnership administration expenses from affiliated parties of $152,129 and $163,845, respectively.  These administration expenses include costs associated with the management of the properties, processing distributions, reporting requirements and communication with the Limited Partners.  During the same periods, the Partnership incurred Partnership administration and property management expenses from unrelated parties of $42,398 and $34,794, 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.

For the nine months ended September 30, 2013 and 2012, the Partnership recognized interest income of $6,277 and $6,085, respectively.

Upon complete disposal of a property or classification of a property as Real Estate Held for Sale, the Partnership includes the operating results and sale of the property in discontinued operations.  In addition, the Partnership reclassifies the prior periods’ operating results of the property to discontinued operations.  For the nine months ended September 30, 2013, the Partnership recognized income from discontinued operations of $1,234,181, representing rental income less property management expenses and depreciation of $105,432 and gain on disposal of real estate of $1,128,749.  For the nine months ended September 30, 2012, the Partnership recognized income from discontinued operations of $181,357, representing rental income less property management expenses and depreciation of $134,562 and gain on disposal of real estate of $46,795.

On February 3, 2012, the Partnership sold its remaining 2.6811% interest in the Arby’s restaurant in Montgomery, Alabama to an unrelated third party.  The Partnership received net sale proceeds of $16,200, which resulted in a net gain of $1,788.  The cost and related accumulated depreciation of the interest sold was $23,049 and $8,637, respectively.

Page 11 of 16

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

During 2012, the Partnership sold its remaining 8.8038% interest in the Winn-Dixie store in Panama City, Florida, in three separate transactions, to unrelated third parties.  The Partnership received total net sale proceeds of $406,884, which resulted in a net gain of $68,108.  The cost and related accumulated depreciation of the interests sold was $408,060 and $69,284, respectively.  For the nine months ended September 30, 2012, the net gain was $45,007.

On August 2, 2013, the Partnership sold its 39% interest in the Scott & White Clinic in College Station, Texas to an unrelated third party.  The Partnership received net sale proceeds of $1,822,494, which resulted in a net gain of $512,842.  At the time of sale, the cost and related accumulated depreciation was $1,433,468 and $123,816, respectively.

In June 2013, the Partnership entered into an agreement to sell its 62% interest in the Applebee’s restaurant in Johnstown, Pennsylvania to an unrelated third party.  On August 23, 2013, the sale closed with the Partnership receiving net sale proceeds of $1,958,905, which resulted in a net gain of $615,907.  At the time of sale, the cost and related accumulated depreciation was $1,682,887 and $339,889, 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, 2013, the Partnership's cash balances increased $3,801,095 as a result of cash generated from the sale of property and cash generated from operating activities in excess of distributions paid to the Partners.  During the nine months ended September 30, 2012, the Partnership's cash balances increased $219,931 as a result of cash generated from the sale of property, which was partially offset by distributions paid to the Partners in excess of cash generated from operating activities.

Net cash provided by operating activities increased from $824,462 in 2012 to $901,514 in 2013 as a result of a decrease in Partnership administration and property management expenses in 2013 and net timing differences in the collection of payments from the tenants and the payment of expenses, which were partially offset by a decrease in total rental and interest income in 2013.

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, 2013 and 2012, the Partnership generated cash flow from the sale of real estate of $3,781,399 and $277,275, respectively.

Page 12 of 16

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

The Partnership's primary use of cash flow, other than investment in real estate, is distribution and redemption payments to Partners.  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.  Redemption payments are paid to redeeming Partners in the fourth quarter of each year.

For the nine months ended September 30, 2013 and 2012, the Partnership declared distributions of $1,182,830 and $881,806, respectively, which were distributed 99% to the Limited Partners and 1% to the General Partners.  The Limited Partners received distributions of $1,171,002 and $872,988 and the General Partners received distributions of $11,828 and $8,818 for the periods, respectively.  In September 2013, the Partnership declared a special distribution of net sale proceeds of $303,030, which resulted in higher distributions declared in 2013 and a higher distributions payable at September 30, 2013.

During the first nine months of 2013 and 2012, the Partnership distributed net sale proceeds of $388,083 and $56,955 to the Limited and General Partners as part of their quarterly distributions, which represented a return of capital of $16.96 and $2.49 per Limited Partnership Unit, respectively.  The Partnership anticipates the remaining net sale proceeds will either be reinvested in additional property or distributed to the Partners in the future.

The Partnership may acquire 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 any number of Units that, when aggregated with all other transfers of Units that have occurred since the beginning of the same calendar year (excluding Permitted Transfers as defined in the Partnership Agreement), would exceed 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 nine months ended September 30, 2013 and 2012, the Partnership did not redeem any Units from the Limited Partners.

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.

The Economy and Market Conditions

The impact of conditions in the economy over the last several years, including the turmoil in the credit markets, has adversely affected many real estate investment funds.  However, the absence of mortgage financing on the Partnership's properties eliminates the risks of foreclosure and debt-refinancing that can negatively impact the value and distributions of leveraged real estate investment funds.  Nevertheless, a prolonged economic downturn may adversely affect the operations of the Partnership's tenants and their cash flows.  If a tenant were to default on its lease obligations, the Partnership's income would decrease, its distributions would likely be reduced and the value of its properties might decline.

Page 13 of 16

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

Off-Balance Sheet Arrangements

As of September 30, 2013 and December 31, 2012, 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.

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.

Page 14 of 16

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, each Limited Partner has the right to present Units to the Partnership for purchase by submitting notice to the Managing General Partner during September of each year.  The purchase price of the Units is based on a formula specified in the Partnership Agreement.  Units tendered to the Partnership are redeemed on October 1st of each year subject to the following limitations.  The Partnership will not be obligated to purchase in any year any number of Units that, when aggregated with all other transfers of Units that have occurred since the beginning of the same calendar year (excluding Permitted Transfers as defined in the Partnership Agreement), would exceed 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.

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.

Page 15 of 16

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, 2013	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 16 of 16

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, 2013	/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, 2013	/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, 2013, 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, 2013

/s/ PATRICK W KEENE

Patrick W. Keene, Chief Financial Officer

AEI Fund Management XXI, Inc.

Managing General Partner

November 13, 2013

XML

Discontinued Operations (Details) - Discontinued Operations (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Discontinued Operations [Abstract]
Rental Income	$ 28,567	$ 66,271	$ 153,847	$ 208,021
Property Management Expenses	178	943	535	1,639
Depreciation	0	23,940	47,880	71,820
Gain on Disposal of Real Estate	1,128,749	23,319	1,128,749	46,795
Income from Discontinued Operations	$ 1,157,138	$ 64,707	$ 1,234,181	$ 181,357

XML

Statement of Income (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Rental Income	$ 278,308	$ 272,545	$ 829,686	$ 811,024
Expenses:
Partnership Administration – Affiliates	50,650	53,588	152,129	163,845
Partnership Administration and Property Management – Unrelated Parties	17,181	7,148	42,398	34,794
Depreciation	98,794	98,794	296,382	296,382
Total Expenses	166,625	159,530	490,909	495,021
Operating Income	111,683	113,015	338,777	316,003
Other Income:
Interest Income	3,126	1,859	6,277	6,085
Income from Continuing Operations	114,809	114,874	345,054	322,088
Income from Discontinued Operations	1,157,138	64,707	1,234,181	181,357
Net Income	1,271,947	179,581	1,579,235	503,445
Net Income Allocated:
General Partners	19,290	1,795	22,363	5,034
Limited Partners	$ 1,252,657	$ 177,786	$ 1,556,872	$ 498,411
Income per Limited Partnership Unit:
Continuing Operations (in Dollars per share)	$ 5.02	$ 5.02	$ 15.08	$ 14.07
Discontinued Operations (in Dollars per share)	$ 50.28	$ 2.82	$ 53.65	$ 7.92
Total – Basic and Diluted (in Dollars per share)	$ 55.30	$ 7.84	$ 68.73	$ 21.99
Weighted Average Units Outstanding – Basic and Diluted (in Shares)	22,653	22,663	22,653	22,663

XML

Payable to AEI Fund Management, Inc.

9 Months Ended

Sep. 30, 2013

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.

XML

Statement of Changes in Partners' Capital (USD $)	General Partner [Member]	Limited Partner [Member]	Total
Balance at Dec. 31, 2011	$ 4,646	$ 16,170,124	$ 16,174,770
Balance (in Shares) at Dec. 31, 2011		22,663.11
Distributions Declared	8,818	872,988	881,806
Net Income	5,034	498,411	503,445
Balance at Sep. 30, 2012	862	15,795,547	15,796,409
Balance (in Shares) at Sep. 30, 2012		22,663.11
Balance at Dec. 31, 2012	686	15,658,370	15,659,056
Balance (in Shares) at Dec. 31, 2012		22,653
Distributions Declared	11,828	1,171,002	1,182,830
Net Income	22,363	1,556,872	1,579,235
Balance at Sep. 30, 2013	$ 11,221	$ 16,044,240	$ 16,055,461
Balance (in Shares) at Sep. 30, 2013		22,653

XML

Organization

9 Months Ended

Sep. 30, 2013

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.

XML

Discontinued Operations

9 Months Ended

Sep. 30, 2013

Discontinued Operations and Disposal Groups [Abstract]

Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]

(5) Discontinued Operations –

On February 3, 2012, the Partnership sold its remaining 2.6811% interest in the Arby’s restaurant in Montgomery, Alabama to an unrelated third party. The Partnership received net sale proceeds of $16,200, which resulted in a net gain of $1,788. The cost and related accumulated depreciation of the interest sold was $23,049 and $8,637, respectively.

During 2012, the Partnership sold its remaining 8.8038% interest in the Winn-Dixie store in Panama City, Florida, in three separate transactions, to unrelated third parties. The Partnership received total net sale proceeds of $406,884, which resulted in a net gain of $68,108. The cost and related accumulated depreciation of the interests sold was $408,060 and $69,284, respectively. For the nine months ended September 30, 2012, the net gain was $45,007.

On August 2, 2013, the Partnership sold its 39% interest in the Scott & White Clinic in College Station, Texas to an unrelated third party. The Partnership received net sale proceeds of $1,822,494, which resulted in a net gain of $512,842. At the time of sale, the cost and related accumulated depreciation was $1,433,468 and $123,816, respectively.

In June 2013, the Partnership entered into an agreement to sell its 62% interest in the Applebee’s restaurant in Johnstown, Pennsylvania to an unrelated third party. On August 23, 2013, the sale closed with the Partnership receiving net sale proceeds of $1,958,905, which resulted in a net gain of $615,907. At the time of sale, the cost and related accumulated depreciation was $1,682,887 and $339,889, respectively.

During the first nine months of 2013 and 2012, the Partnership distributed net sale proceeds of $388,083 and $56,955 to the Limited and General Partners as part of their quarterly distributions, which represented a return of capital of $16.96 and $2.49 per Limited Partnership Unit, respectively.

The financial results for these properties are reflected as Discontinued Operations in the accompanying financial statements. The following are the results of discontinued operations:

		Three Months Ended September 30				Nine Months Ended September 30
		2013		2012		2013		2012
Rental Income	$	28,567	$	66,271	$	153,847	$	208,021
Property Management Expenses		178		943		535		1,639
Depreciation		0		23,940		47,880		71,820
Gain on Disposal of Real Estate		1,128,749		23,319		1,128,749		46,795
Income from Discontinued Operations	$	1,157,138	$	64,707	$	1,234,181	$	181,357

XML

Reclassification

9 Months Ended

Sep. 30, 2013

Disclosure Text Block [Abstract]

Reclassifications [Text Block]

(3) Reclassification –

Certain items related to discontinued operations in the prior year’s financial statements have been reclassified to conform to 2013 presentation. These reclassifications had no effect on Partners’ capital, net income or cash flows.

XML

Balance Sheet (Parentheticals)(Limited Partner [Member])	Sep. 30, 2013	Dec. 31, 2012
Limited Partners, units authorized	24,000	24,000
Limited Partners, units issued	22,653	22,653
Limited Partners, units outstanding	22,653	22,653

XML

Discontinued Operations (Tables)

9 Months Ended

Sep. 30, 2013

Discontinued Operations and Disposal Groups [Abstract]

Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]

Discontinued Operations

		Three Months Ended September 30				Nine Months Ended September 30
		2013		2012		2013		2012
Rental Income	$	28,567	$	66,271	$	153,847	$	208,021
Property Management Expenses		178		943		535		1,639
Depreciation		0		23,940		47,880		71,820
Gain on Disposal of Real Estate		1,128,749		23,319		1,128,749		46,795
Income from Discontinued Operations	$	1,157,138	$	64,707	$	1,234,181	$	181,357

XML

Statement of Cash Flows (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash Flows from Operating Activities:
Net Income	$ 1,579,235	$ 503,445
Adjustments to Reconcile Net Income To Net Cash Provided by Operating Activities:
Depreciation	344,262	368,202
Gain on Sale of Real Estate	1,128,749	46,795
Increase (Decrease) in Payable to AEI Fund Management, Inc.	85,555	(2,434)
Increase (Decrease) in Unearned Rent	21,211	2,044
Total Adjustments	(677,721)	321,017
Net Cash Provided By Operating Activities	901,514	824,462
Cash Flows from Investing Activities:
Proceeds from Sale of Real Estate	3,781,399	277,275
Cash Flows from Financing Activities:
Distributions Paid to Partners	881,818	881,806
Net Increase (Decrease) in Cash	3,801,095	219,931
Cash, beginning of period	2,259,911	1,934,854
Cash, end of period	$ 6,061,006	$ 2,154,785

XML

Balance Sheet (USD $)	Sep. 30, 2013	Dec. 31, 2012
Current Assets:
Cash	$ 6,061,006	$ 2,259,911
Real Estate Held for Investment:
Land	3,681,363	4,403,667
Buildings and Equipment	9,879,315	12,273,366
Accumulated Depreciation	2,811,196	2,930,639
Real Estate Held for Investment, Net	10,749,482	13,746,394
Total Assets	16,810,488	16,006,305
Current Liabilities:
Payable to AEI Fund Management, Inc.	126,744	41,189
Distributions Payable	594,952	293,940
Unearned Rent	33,331	12,120
Total Current Liabilities	755,027	347,249
Partners’ Capital:
General Partners	11,221	686
Limited Partners – 24,000 Units authorized; 22,653 Units issued and outstanding	16,044,240	15,658,370
Total Partners' Capital	16,055,461	15,659,056
Total Liabilities and Partners' Capital	16,810,488	16,006,305
Limited Partner [Member]
Partners’ Capital:
Total Partners' Capital	$ 16,044,240	$ 15,658,370

XML

Accounting Policies, by Policy (Policies)	9 Months Ended
	Sep. 30, 2013
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.

XML

Discontinued Operations (Details) (USD $)	9 Months Ended		0 Months Ended	9 Months Ended		0 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Feb. 03, 2012 Arby's Montgomery AL	Dec. 31, 2012 Winn Dixie Panama City FL	Sep. 30, 2012 Winn Dixie Panama City FL	Aug. 02, 2013 Scott White College Station TX	Aug. 23, 2013 Applebees Johnstown PA
Discontinued Operations (Details) [Line Items]
Significant Acquisitions and Disposals, Acquisition Costs or Sale Proceeds			$ 16,200	$ 406,884		$ 1,822,494	$ 1,958,905
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax			1,788	68,108	45,007	512,842	615,907
SEC Schedule III, Real Estate, Cost of Real Estate Sold			23,049	408,060		1,433,468	1,682,887
SEC Schedule III, Real Estate Accumulated Depreciation, Real Estate Sold			8,637	69,284		123,816	339,889
Sale Proceeds Distribution Made To Member Or Limited Partner	$ 388,083	$ 56,955
Return Of Capital Distribution Made To Member Or Limited Partner Distributions Paid Per Unit (in Dollars per share)	$ 16.96	$ 2.49

XML

Fair Value Measurements

9 Months Ended

Sep. 30, 2013

Fair Value Disclosures [Abstract]

Fair Value Disclosures [Text Block]

(7) Fair Value Measurements –

As of September 30, 2013, the Partnership had no assets or liabilities measured at fair value on a recurring basis or nonrecurring basis.

XML

Basis of Accounting

9 Months Ended

Sep. 30, 2013

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 generally accepted accounting principles 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.

XML

Organization (Details) (USD $)	Jan. 31, 1997	Apr. 14, 1995
Accounting Policies [Abstract]
Capital Units, Value		$ 1,000
Limited Partners' Capital Account, Units Outstanding (in Shares)	24,000	1,500
Limited Partners' Contributed Capital	24,000,000	1,500,000
General Partners' Contributed Capital	$ 1,000

XML

Document And Entity Information (USD $)	9 Months Ended
	Sep. 30, 2013
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	22,653
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, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q3