ADTRAN Holdings, Inc. Debt Disclosure

Note 10 – Credit Agreement

As of December 31, 2025 and 2024, the estimated fair value of our revolving credit agreement, approximates the carrying value. As of December 31, 2025 and 2024, the weighted average interest rate on our revolving credit agreement was 8.98% and 8.64%, respectively.

Revolving Credit Agreement

On July 18, 2022, ADTRAN, Inc., as the borrower ("U.S. Borrower"), and the Company entered into a credit agreement with a syndicate of banks, including Wells Fargo Bank, National Association, as administrative agent (“Administrative Agent”), and the other lenders named therein (the “Original Credit Agreement”), as amended by the First Amendment to Credit Agreement, dated August 9, 2023 (“Amendment No. 1”), the Second Amendment to Credit Agreement, dated January 16, 2024 (“Amendment No. 2”), the Third Amendment to Credit Agreement, dated March 12, 2024 (“Amendment No. 3”), the Fourth Amendment to Credit Amendment, dated June 4, 2024 among Adtran Networks (the "German Borrower") and the parties set forth above ("Amendment No. 4") and the Fifth Amendment to Credit Agreement and Waiver, dated May 6, 2025, among the German Borrower and the parties set forth above (“Amendment No. 5”; the Original Credit Agreement as amended by Amendment No. 1, Amendment No. 2. Amendment No. 3, Amendment No. 4 and Amendment No. 5, the “Existing Credit Agreement”).

On September 16, 2025, the U.S. Borrower, the German Borrower, and the lenders party thereto, including the Administrative Agent, entered into the Sixth Amendment and Consent to Credit Agreement, dated September 16, 2025 (“Amendment No. 6”; the Existing Credit Agreement as amended by Amendment No. 6, the “Amended Credit Agreement”). Amendment No. 6, among other things, (i) provides for a consent from the lenders to the issuance by the Company of new unsecured convertible indebtedness in an amount not to exceed $230.0 million, notwithstanding the cap on the amount of Permitted Convertible Indebtedness (as defined in the Amended Credit Agreement) the Company is permitted to incur, (ii) requires that the net cash proceeds of the new unsecured convertible indebtedness be used to (a) repay outstanding revolving credit loans under the Amended Credit Agreement, (b) pay fees, costs, and expenses related to Amendment No. 6 and the issuance of the new unsecured convertible indebtedness and (c) cash collateralize the obligations of the Company and its subsidiaries under the Amended Credit Agreement (with such cash only being permitted to be withdrawn for the purpose of financing the purchase of additional outstanding shares of Equity Interests (as defined in the Amended Credit Agreement) of the German Borrower that were not owned by the Company and its subsidiaries as of August 9, 2023 pursuant to Section 5, paragraph 1 of the DPLTA), and (iii) after the prepayment contemplated in the foregoing clause (ii)(a) and the provision of cash collateral contemplated in the foregoing clause (ii)(c), amends provisions governing the Subline (as defined below) to provide that future prepayments in respect of borrowings under the Subline will no longer permanently reduce the commitments in respect of the Subline.

As of December 31, 2025, the Amended Credit Agreement provided for a secured revolving credit facility of up to $350.0 million of borrowings, $50.0 million of which is solely available to the German Borrower.

As of December 31, 2025, the Company’s borrowings under the revolving line of credit were $25.0 million. The credit facilities provided under the Amended Credit Agreement mature in July 2027, but the U.S. Borrower may request extensions subject to customary conditions. In addition, the U.S. Borrower may utilize up to $50.0 million of the $350.0 million total revolving facility for the issuance of letters of credit. As of December 31, 2025, the U.S. Borrower had a total of $5.8 million in letters of credit under the Amended Credit Agreement, leaving a net amount (after giving effect to the $25.0 million of outstanding borrowings described above) of $319.2 million available for future borrowings, based on debt covenant compliance metrics. Any future credit extensions under the Amended Credit Agreement are subject to customary conditions precedent. The proceeds of any loans may be used as described above, as well as for working capital and other general corporate purposes.

Moreover, the Amended Credit Agreement provides for a sublimit under the existing $350.0 million revolving commitments in an aggregate amount of $50.0 million (“Subline”), which Subline is available for borrowings by the German Borrower. The Company had no borrowings under the Subline as of December 31, 2025. The existing swing line sublimit and letter of credit sublimit under the Amended Credit Agreement remain available to the U.S. Borrower (and not to the German Borrower). Otherwise, the loans under the Subline are subject to substantially the same terms and conditions under the Amended Credit Agreement (including with respect to the interest rate and maturity date) as the other existing revolving commitments.

All U.S. borrowings under the Amended Credit Agreement bear interest at a rate tied to the Base Rate (as defined in the Amended Credit Agreement) or SOFR, at the Company’s option, and all E.U. borrowings bear interest at a rate tied to the Euro Interbank Offered Rate as administered by the European Money Markets Institute (or a comparable or successor administrator approved by the Administrative Agent), in each case plus applicable margins which vary based on the consolidated net leverage ratio of the Company and its subsidiaries as determined pursuant to the terms of the Amended Credit Agreement. Default interest is 2.00% per annum in excess of the rate otherwise applicable.

The Company made certain representations and warranties to the lenders in the Amended Credit Agreement that are customary for credit arrangements of this type. The Company also agreed to maintain a Consolidated Total Net Leverage Ratio of 5.00x, a Consolidated Senior Secured Net Leverage Ratio of 3.25x (4.0x to 3.5x during a “Springing Covenant Period,” as defined below) and a Consolidated Fixed Charge Coverage Ratio of 1.25x (as such ratios are defined in the Amended Credit Agreement). A “Springing Covenant Event” occurs when at least sixty percent (60.0%) of the outstanding shares of Adtran Networks that were not owned by the Company and its subsidiaries as of August 9, 2023 have been tendered and purchased by the Company. Upon the occurrence of a Springing Covenant Event, the Company will enter a “Springing Covenant Period”, defined as the fiscal quarter in which a Springing Covenant Event occurs and the three (3) consecutive fiscal quarters thereafter. During a Springing Covenant Period, the Company’s leverage ratios are increased. In addition, the cash and cash equivalents of the credit parties must be at least $50.0 million and the cash and cash equivalents of the Company and its subsidiaries must be at least $70.0 million. As of December 31, 2025, the Company was in compliance with all covenants under the Credit Agreement.

The Amended Credit Agreement also contains customary events of default, such as misrepresentation and a default in the performance or observance of any covenant (subject to customary cure periods and materiality thresholds). Upon the occurrence and during the continuance of an event of default, the Administrative Agent is entitled to take various actions, including the acceleration of all amounts due under the Amended Credit Agreement.

All obligations under the Amended Credit Agreement (including under the Subline) are guaranteed by the U.S. Borrower and certain subsidiaries of the U.S. Borrower (“Full Facility Guarantors”). To secure such guarantees, the U.S. Borrower and the Full Facility Guarantors have granted security interests in favor of the Administrative Agent over substantially all of their tangible and intangible assets, and the U.S. Borrower has granted mortgages in favor of the Administrative Agent over certain owned real estate assets. Certain of the German Borrower's subsidiaries (the “Subline Guarantors”) have also provided a guarantee solely of the obligations in respect of the Subline. Furthermore, to secure such guarantees, the German Borrower and the Subline Guarantors have granted security interests in favor of the Administrative Agent over substantially all of their tangible and intangible assets. Upon repayment in full and termination of the Subline, the guarantees by the Subline Guarantors and the liens granted by the German Borrower and the Subline Guarantors to secure obligations under the Subline will be released.