The accompanying unaudited consolidated financial statements of ADTRAN^®, Inc. and its subsidiaries (ADTRAN) have been prepared pursuant to the rules and regulations for reporting on Quarterly Reports on Form 10-Q. Accordingly, certain information and notes required by generally accepted accounting principles for complete financial statements are not included herein. The December 31, 2017 Consolidated Balance Sheet is derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States.

In the opinion of management, all adjustments necessary to fairly state these interim statements have been recorded and are of a normal and recurring nature. The results of operations for an interim period are not necessarily indicative of the results for the full year. The interim statements should be read in conjunction with the financial statements and notes thereto included in ADTRAN’s Annual Report on Form 10-K for the year ended December 31, 2017, filed on February 23, 2018 with the SEC.

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expense during the reporting period. Our more significant estimates include the obsolete and excess inventory reserves, warranty reserves, customer rebates, determination of the deferred revenue components of multiple element sales agreements, estimated costs to complete obligations associated with deferred revenues, estimated income tax provision and income tax contingencies, the fair value of stock-based compensation, impairment of goodwill, valuation and estimated lives of intangible assets, estimated pension liability, fair value of investments, and the evaluation of other-than-temporary declines in the value of investments. Actual amounts could differ significantly from these estimates.

In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-02, Leases (Topic 842). ASU 2016-02 requires an entity to recognize lease assets and lease liabilities on the balance sheet and to disclose key information about the entity's leasing arrangements. In July 2018, the FASB issued ASU 2018-10, Codification Improvements to Topic 842, Leases, which clarified certain aspects of ASU 2016-02, as well as, ASU 2018-11, Leases (Topic 842), Targeted Improvements, which provides for an optional transition method that allows for the application of current legacy guidance, including its disclosure requirements, in the comparative periods presented in the year of adoption. Otherwise, Topic 842 must be adopted by a modified retrospective method, with elective reliefs, which requires application of the new guidance for all periods presented. The Company plans to use the optional transition method when adopting the new standard. ASU 2016-02, ASU 2018-10 and ASU 2018-11 are effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. We anticipate the adoption of these ASUs will have a material increase in the assets and liabilities of our consolidated balance sheets; however, we do not believe adoption will have a material effect on our results of operations. We believe the most significant effect relates to our accounting for operating leases for office space.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. ASU 2016-13 requires the measurement and recognition of expected credit losses for financial instruments held at amortized cost. ASU 2016-13 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, with early adoption permitted. We are currently evaluating the effect ASU 2016-13 will have on our consolidated financial statements.

In January 2017, the FASB issued ASU 2017-04, Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. ASU 2017-04 simplifies the measurement of goodwill by eliminating step 2 of the goodwill impairment test. Under ASU 2017-04, entities will be required to compare the fair value of a reporting unit to its carrying amount and recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. ASU 2017-04 is effective for annual or interim impairment tests performed in fiscal years beginning after December 15, 2019, with early adoption permitted for annual or interim impairment tests performed on testing dates after January 1, 2017. The amendments should be applied prospectively. We are currently evaluating whether to early adopt ASU 2017-04, but we do not expect it will have a material effect on our consolidated financial statements.

In March 2017, the FASB issued ASU 2017-08, Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities, which shortens the amortization period for the premium on certain purchased callable debt securities to the earliest call date. ASU 2017-08 is effective for fiscal years and interim periods within those fiscal years, beginning after December 15, 2018 with early adoption permitted. The amendments should be applied through a modified-retrospective transition approach that requires a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. We are currently evaluating the effect of ASU 2017-08, but we do not expect it will have a material effect on our consolidated financial statements.

In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. ASU 2017-12 expands and refines hedge accounting for both financial and non-financial risk components, aligns the recognition and presentation of the effects of hedging instruments and hedge items in the financial statements, and includes certain targeted improvements to ease the application of current guidance related to the assessment of hedge effectiveness. ASU 2017-12 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018, with early adoption permitted. We are currently evaluating the effect ASU 2017-12 will have on our consolidated financial statements.

In February 2018, the FASB issued ASU 2018-02, Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Comprehensive Income. ASU 2018-02 allows for an optional reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017. ASU 2018-02 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018, with early adoption permitted. We are currently evaluating whether to reclassify stranded tax effects related to the Tax Cuts and Jobs Act of 2017, but we do not expect ASU 2018-02 will have a material effect on our consolidated financial statements.

In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820) Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement, which changes the fair value measurement disclosure requirements of ASC 820, Fair Value Measurement. The amendments in this ASU are the result of a broader disclosure project called, Concepts Statement No. 8 - Conceptual Framework for Financial Reporting — Chapter 8, Notes to Financial Statements, which the FASB finalized on August 28, 2018. The FASB used the guidance in the Concepts Statement to improve the effectiveness of ASC 820’s disclosure requirements. ASU 2018-13 provides users of financial statements with information about assets and liabilities measured at fair value in the statement of financial position or disclosed in the notes to the financial statements. More specifically ASU 2018-13 requires disclosures about the valuation techniques and inputs that are used to arrive at measures of fair value, including judgments and assumptions that are made in determining fair value. In addition, ASU 2018-13 requires disclosures regarding the uncertainty in the fair value measurements as of the reporting date and how changes in fair value measurements affect performance and cash flows. ASU 2018-13 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. We are currently evaluating the effect of ASU 2018-13, but we do not expect it will have a material effect on our financial statement disclosures.

In August 2018, the FASB issued ASU 2018-14, Compensation-Retirement Benefits-Defined Benefit Plans-General (Subtopic 715-20): Disclosure Framework-Changes to the Disclosure Requirements for Defined Benefit Plans, which makes changes to and clarifies the disclosure requirements related to defined benefit pension and other postretirement plans. ASU 2018-14 requires additional disclosures related to the reasons for significant gains and losses affecting the benefit obligation and an explanation of any other significant changes in the benefit obligation or plan assets that are not otherwise apparent in other disclosures required by ASC 715. ASU 2018-14 also clarifies the guidance in ASC 715 to require disclosure of the projected benefit obligation (PBO) and fair value of plan assets for pension plans with PBOs in excess of plan assets and the accumulated benefit obligation (ABO) and fair value of plan assets for pension plans with ABOs in excess of plan assets. ASU 2018-14 is effective for public business entities for fiscal years ending after December 15, 2020. We are currently evaluating the effect of ASU 2018-14, but we do not expect it will have a material effect on our financial statement disclosures.

In August 2018, the FASB issued ASU 2018-15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40), Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract. ASU 2018-15 clarifies certain aspects of ASU 2015-05, Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement. Specifically, ASU 2018-15 aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementations costs incurred to develop or obtain internal use software. ASU 2018-15 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019, with early adoption permitted. We are currently evaluating whether to early adopt, but we do not expect it will have a material effect on our consolidated financial statements.

During 2018, we adopted the following accounting standards, which had the following effects on our consolidated financial statements:

In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606), which supersedes the revenue recognition requirements in Topic 605, Revenue Recognition, including most industry-specific revenue recognition guidance throughout the Industry Topics of the Codification. The core principle of ASU 2014-09 is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. In August 2015, the FASB issued ASU 2015-14, which deferred the effective date of ASU 2014-09 to fiscal years beginning after December 31, 2017, and interim periods within those fiscal years, with early adoption permitted for reporting periods beginning after December 15, 2016. Subsequently, the FASB issued ASUs in 2016 containing implementation guidance related to ASU 2014-09, including: ASU 2016-08, Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net), which is intended to improve the operability and understandability of the implementation guidance on principal versus agent considerations; ASU 2016-10, Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing, which is intended to clarify two aspects of Topic 606: identifying performance obligations and the licensing implementation guidance; ASU 2016-12, Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients, which contains certain provisions and practical expedients in response to identified implementation issues; and ASU 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers, which is intended to clarify the Codification and/or to correct unintended application of guidance. ASU 2014-09 allows for either full retrospective or modified retrospective adoption. We adopted ASU 2014-09 and the related ASUs on January 1, 2018 using the modified retrospective method, which was applied to all contracts on the date of initial adoption.

These ASUs primarily affected our network implementation service revenue performance obligations and contract costs. We are using the “output method” to measure network implementation services progress, which 1) accelerates revenue recognition for certain performance obligations related to service revenue arrangements that were previously deferred until customer acceptance and 2) requires capitalization and amortization of the incremental costs of obtaining a contract as described below.

In connection with the adoption of the new revenue standard, effective January 1, 2018, we adopted ASC 340-40, Other Assets and Deferred Costs – Contracts with Customers, with respect to capitalization and amortization of incremental costs of obtaining a contract. As a result, certain costs of obtaining a contract, including sales commissions, will be capitalized, as the guidance requires the capitalization of all incremental costs incurred to obtain a contract with a customer that it would not have incurred if the contract had not been obtained, provided the costs are recoverable. The primary effect was the capitalization of certain sales commissions for our extended maintenance and support contracts in excess of one year and amortization of those costs over the period that the related revenue is recognized.

The cumulative effect of the changes made to our Consolidated Balance Sheet on January 1, 2018 for the adoption of ASU 2014-09 and the related ASUs was as follows:

(In thousands)	Balance at December 31, 2017		Adjustments due to ASU 2014-09			Balance at January 1, 2018
Other receivables	$	26,578	$	374		$	26,952
Deferred tax assets, net	$	23,428	$	(96	)	$	23,332
Retained earnings	$	922,178	$	278		$	922,456

The effect of the adoption of ASU 2014-09 and the related ASUs on our financial statements was as follows:

	For the three months ended September 30, 2018
(In thousands)	As Reported		Balances Without Adoption of ASC 606		Effect of Adoption of ASC 606
Sales
Products	$	121,043	$	120,588	$	455
Services	$	19,292	$	17,932	$	1,360
Cost of Sales
Products	$	69,943	$	69,754	$	189
Services	$	11,944	$	11,046	$	898

Income before benefit for income taxes	$	3,220	$	2,492	$	728
Benefit for income taxes	$	4,369	$	3,382	$	987
Net income	$	7,589	$	5,874	$	1,715

	For the nine months ended September 30, 2018
(In thousands)	As Reported			Balances Without Adoption of ASC 606			Effect of Adoption of ASC 606
Sales
Products	$	341,359		$	341,464		$	(105	)
Services	$	47,830		$	46,062		$	1,768
Cost of Sales
Products	$	208,184		$	208,480		$	(296	)
Services	$	32,828		$	31,743		$	1,085

Loss before benefit for income taxes	$	(22,784	)	$	(23,658	)	$	874
Benefit for income taxes	$	11,889		$	10,938		$	951
Net loss	$	(10,895	)	$	(12,720	)	$	1,825

	As of September 30, 2018
(In thousands)	As Reported		Balances Without Adoption of ASC 606		Effect of Adoption of ASC 606
Assets
Other receivables	$	30,084	$	27,917	$	2,167
Inventory	$	106,060	$	106,402	$	(342	)
Equity
Retained earnings	$	900,324	$	898,499	$	1,825

In January 2016, the FASB issued ASU 2016-01, Financial Instruments — Overall: Recognition and Measurement of Financial Assets and Financial Liabilities, which addresses certain aspects of the recognition, measurement, presentation and disclosure of financial instruments. Subsequently, the FASB issued ASU 2018-03, Technical Corrections and Improvements to Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities, which issued technical corrections and improvements intended to clarify certain aspects of ASU 2016-01. ASU 2016-01 was effective beginning January 1, 2018 and we now recognize any changes in the fair value of certain equity investments in net income as prescribed by the new standard rather than in other comprehensive income. We adopted ASU 2016-01 on January 1, 2018 using the modified retrospective method, which resulted in a $3.2 million reclassification of net unrealized gains from accumulated other comprehensive income to opening retained earnings. ASU 2018-03 is effective for us with the interim period beginning after June 15, 2018. See Note 7 of Notes to Consolidated Financial Statements for additional information.

In March 2017, the FASB issued ASU 2017-07, Compensation – Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. ASU 2017-07 amends ASC 715, Compensation — Retirement Benefits, to require employers that present a measure of operating income in their statements of earnings to include only the service cost component of net periodic pension cost and net periodic postretirement benefit cost in operating expenses (together with other employee compensation costs). The other components of net benefit cost, including amortization of prior service cost/credit, and settlement and curtailment effects, are to be included in non-operating expenses. We adopted ASU 2017-07 on January 1, 2018. We retrospectively adopted the presentation of service cost separate from other components of net periodic pension costs. As a result, $0.1 million and $0.3 million have been reclassified from cost of sales, selling, general and administrative expenses, and research and development expense to other income (expense), net for the three and nine months ended September 30, 2017, respectively.