Other Events On August 6, 2026, the Company issued a press release announcing the approval by the Board of Directors (the "Board") of the Company of the declaration of a cash dividend of $0.20 per share, payable on September 15, 2026, to stockholders of record at the close of business on September 1, 2026. A copy of the Company’s press release is attached hereto as Exhibit 99.3 and hereby incorporated by reference.

Results of Operations and Financial Condition On August 6, 2026, Advanced Drainage Systems, Inc. (the "Company") issued a press release setting forth the Company’s unaudited results for the fiscal first quarter ended June 30, 2026. A copy of the Company’s press release with the results is being furnished as Exhibit 99.1 and hereby incorporated by reference. The information furnished pursuant to this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of t…

Results of Operations and Financial Condition On May 21, 2026, Advanced Drainage Systems, Inc. (the "Company") issued a press release setting forth the Company’s unaudited results for the fourth quarter and fiscal year ended March 31, 2026. A copy of the Company’s press release with the results is being furnished as Exhibit 99.1 and hereby incorporated by reference. The information furnished pursuant to this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Sectio…

Other Events On May 21, 2026, the Company issued a press release announcing the approval by the Board of Directors (the "Board") of the Company of the declaration of a cash dividend of $0.20 per share, payable on June 15, 2026, to stockholders of record at the close of business on June 1, 2026. A copy of the Company’s press release is attached hereto as Exhibit 99.3 and hereby incorporated by reference.

Regulation FD Disclosure As previously reported in the Form 10-K and the Form 8-K filed on May 21, 2026 for the fiscal year ended March 31, 2026 by Advanced Drainage Systems, Inc. (the “Company”) or (“ADS”), following the acquisition of National Diversified Sales (“NDS”) we realigned our reportable segments to align with the manner in which the Chief Operating Decision Maker (“CODM”) assesses performance and makes resource allocation decisions (the “Segment Realignment”). Our revised reportab…

Regulation FD Disclosure. On February 27, 2026 (the “Redemption Date”), the Company redeemed in full its outstanding 5.000% Senior Notes due 2027 (the “2027 Notes”) in the original aggregate principal amount of $350,000,000. The 2027 Notes were redeemed at a redemption price equal to 100% of the principal amount of the 2027 Notes plus accrued and unpaid interest, if any, to, but excluding, the Redemption Date. The information in

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information contained in and incorporated into

Entry into a Material Definitive Agreement. Senior Notes Due 2034 On February 27, 2026, Advanced Drainage Systems, Inc. (the “Company”) issued $500.0 million aggregate principal amount of its 5.375% senior notes due 2034 (the “Notes”) pursuant to an Indenture, dated February 27, 2026 (the “Indenture”), among the Company, the guarantors party thereto (as defined below, the “Guarantors”) and U.S. Bank Trust Company, National Association, as Trustee (the “Trustee”). The Notes are guaranteed by e…

Regulation FD Disclosure Pricing of 5.375% Senior Notes due 2034 On February 12, 2026, Advanced Drainage Systems, Inc. (the “Company”) issued a press release announcing that it had priced a private offering (the “Private Offering”) of $500 million aggregate principal amount of 5.375% senior unsecured notes due 2034 (the “Notes”). The Private Offering is expected to close on February 27, 2026, subject to customary closing conditions. The full text of the press release is attached hereto as Exh…

Other Events On February 5, 2026, the Company announced a $1 billion increase in the size of the Company’s existing stock repurchase program (the “Repurchase Program”). As of the date hereof there was approximately $147.7 million of remaining repurchase authority under the Repurchase Program, bringing the total repurchase authority under the Repurchase Program with the announced increase to $1.148 billion. Repurchases of shares of common stock will be made in the open market or in privately n…

Results of Operations and Financial Condition On February 5, 2026, Advanced Drainage Systems, Inc. (the "Company") issued a press release setting forth the Company’s unaudited results for the fiscal third quarter ended December 31, 2025 and announcing a $1 billion increase to its stock repurchase program. A copy of the Company’s press release with the results is being furnished as Exhibit 99.1 and hereby incorporated by reference. The information furnished pursuant to this Item 2.02, includin…

Regulation FD Disclosure On February 2, 2026, the Company issued a press release announcing the completion of the acquisition of NDS, as described in

Completion of Acquisition or Disposition of Assets On February 2, 2026, Advanced Drainage Systems, Inc. (the “Company”) completed its previously announced acquisition of the outstanding capital stock of certain indirect subsidiaries of NORMA Group SE (“Norma Group”), a European company ( Societas Europaea ) incorporated under the laws of Germany, which comprise substantially all of Norma Group’s water management business known as National Diversified Sales (“NDS”), subject to the terms and co…

Results of Operations and Financial Condition On November 6, 2025, Advanced Drainage Systems, Inc. (the "Company") issued a press release setting forth the Company’s unaudited results for the fiscal second quarter ended September 30, 2025. A copy of the Company’s press release with the results is being furnished as Exhibit 99.1 and hereby incorporated by reference. The information furnished pursuant to this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section…

Other Events On November 6, 2025, the Company issued a press release announcing the approval by the Board of Directors (the "Board") of the Company of the declaration of a cash dividend of $0.18 per share, payable on December 15, 2025, to stockholders of record at the close of business on December 1, 2025. A copy of the Company’s press release is attached hereto as Exhibit 99.3 and hereby incorporated by reference.

Regulation FD Disclosure. On September 23, 2025, the Company issued a press release announcing the proposed acquisition of NDS. A copy of the Company’s press release is attached hereto as Exhibit 99.1 and hereby incorporated by reference. At 9:00 a.m. (Eastern Time) on September 23, 2025, the Company will host a webcast to discuss the proposed acquisition of NDS. Attached as Exhibit 99.2 and incorporated by reference herein is the investor presentation that will be used by the Company during…

Entry Into a Material Definitive Agreement. On September 23, 2025, Advanced Drainage Systems, Inc. (the “Company”) and NORMA Group SE (“Norma Group”), a European company ( Societas Europaea ) incorporated under the laws of Germany, entered into a Master Share Purchase Agreement (the “Purchase Agreement”), pursuant to which Norma Group has agreed to sell to the Company the outstanding capital stock of certain indirect subsidiaries, which comprise substantially all of Norma Group’s water manage…

Other Events On August 7, 2025, the Company issued a press release announcing the approval by the Board of Directors (the "Board") of the Company of the declaration of a cash dividend of $0.18 per share, payable on September 15, 2025, to stockholders of record at the close of business on August 29, 2025. A copy of the Company’s press release is attached hereto as Exhibit 99.3 and hereby incorporated by reference.

Results of Operations and Financial Condition On August 7, 2025, Advanced Drainage Systems, Inc. (the "Company") issued a press release setting forth the Company’s unaudited results for the fiscal first quarter ended June 30, 2025. A copy of the Company’s press release with the results is being furnished as Exhibit 99.1 and hereby incorporated by reference. The information furnished pursuant to this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of t…

Executive Vice President, Supply Chain — Darin Harvey: The Executive Vice President of Supply Chain is resigning, which constitutes a genuine departure of a senior officer, though the stated lack of dispute suggests a neutral or planned exit rather than a crisis.

Other Events On May 15, 2025, the Company issued a press release announcing the approval by the Board of Directors (the "Board") of the Company of the declaration of a cash dividend of $0.18 per share, payable on June 16, 2025, to stockholders of record at the close of business on May 30, 2025. A copy of the Company’s press release is attached hereto as Exhibit 99.3 and hereby incorporated by reference.

Results of Operations and Financial Condition On May 15, 2025, Advanced Drainage Systems, Inc. (the "Company") issued a press release setting forth the Company’s unaudited results for the fourth quarter and fiscal year ended March 31, 2025. A copy of the Company’s press release with the results is being furnished as Exhibit 99.1 and hereby incorporated by reference. The information furnished pursuant to this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Sectio…

Other Events On February 6, 2025, the Company issued a press release announcing the approval by the Board of Directors (the "Board") of the Company of the declaration of a cash dividend of $0.16 per share, payable on March 14, 2025, to stockholders of record at the close of business on February 28, 2025. A copy of the Company’s press release is attached hereto as Exhibit 99.3 and hereby incorporated by reference.

Results of Operations and Financial Condition On February 6, 2025, Advanced Drainage Systems, Inc. (the "Company") issued a press release setting forth the Company’s unaudited results for the fiscal third quarter ended December 31, 2024. A copy of the Company’s press release with the results is being furnished as Exhibit 99.1 and hereby incorporated by reference. The information furnished pursuant to this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 1…

Results of Operations and Financial Condition On November 8, 2024, Advanced Drainage Systems, Inc. (the "Company") issued a press release setting forth the Company’s unaudited results for the fiscal second quarter ended September 30, 2024. A copy of the Company’s press release with the results is being furnished as Exhibit 99.1 and hereby incorporated by reference. The information furnished pursuant to this Item 2.02, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section…