# EDGAR Filing Document

**Accession Number:** 0001604028
**File Stem:** 0001604028-25-000035
**Filing Date:** 2025-9
**Character Count:** 32101
**Document Hash:** dac95c29391dbd0516122c9ae9518e19
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001604028-25-000035.hdr.sgml**: 20250916

**ACCESSION NUMBER**: 0001604028-25-000035

**CONFORMED SUBMISSION TYPE**: 11-K

**PUBLIC DOCUMENT COUNT**: 35

**CONFORMED PERIOD OF REPORT**: 20250331

**FILED AS OF DATE**: 20250916

**DATE AS OF CHANGE**: 20250916

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** ADVANCED DRAINAGE SYSTEMS, INC.
- **CENTRAL INDEX KEY:** 0001604028
- **STANDARD INDUSTRIAL CLASSIFICATION:** PLASTICS FOAM PRODUCTS [3086]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 510105665
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 0331

**FILING VALUES:**
- **FORM TYPE:** 11-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36557
- **FILM NUMBER:** 251317700

**BUSINESS ADDRESS:**
- **STREET 1:** 4640 TRUEMAN BOULEVARD
- **CITY:** HILLIARD
- **STATE:** OH
- **ZIP:** 43026
- **BUSINESS PHONE:** 614-658-0050

**MAIL ADDRESS:**
- **STREET 1:** 4640 TRUEMAN BOULEVARD
- **CITY:** HILLIARD
- **STATE:** OH
- **ZIP:** 43026

?xml version='1.0' encoding='ASCII'? wms-20250331

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

**FORM 11-K**

(Mark One)

☒ ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES AND EXCHANGE ACT OF 1934

For the Fiscal Year Ended March 31, 2025

OR

☐ TRANSITION REPORT PURSUANT TO SECTION 15(d)OF THE SECURITIES AND EXCHANGE ACT OF 1934

For the transition period from _______ to _______

Commission file number 001-365578

A.Full title of the plan and the address of the plan, if different from that of the issuer named below:

**ADVANCED DRAINAGE SYSTEMS, INC. RETIREMENT AND STOCK OWNERSHIP PLAN**

B.Name of issuer of the securities held pursuant to the plan and the address of its principal executive office:

**ADVANCED DRAINAGE SYSTEMS, INC.**

**4640 Trueman Boulevard** 

**Hilliard, Ohio 43026**

------

**TABLE OF CONTENTS**

---

| | |
|:---|:---|
| | **Page** |
| <u>[Report of Independent Registered Public Accounting Firm](#i515d031fff4e4e5fa26393bcb5bc1593_10)</u> | <u>[3](#i515d031fff4e4e5fa26393bcb5bc1593_10)</u> |
| Financial Statements: | |
| &nbsp;&nbsp;&nbsp;&nbsp;<u>[Statements of Net Assets Available for Benefits as of March 31, 2025 and 2024](#i515d031fff4e4e5fa26393bcb5bc1593_13)</u> | <u>[4](#i515d031fff4e4e5fa26393bcb5bc1593_13)</u> |
| &nbsp;&nbsp;&nbsp;&nbsp;<u>[Statements of Changes in Net Assets Available for Benefits for the Years Ended March 31, 2025 and March 31, 2024](#i515d031fff4e4e5fa26393bcb5bc1593_16)</u> | <u>[5](#i515d031fff4e4e5fa26393bcb5bc1593_16)</u> |
| &nbsp;&nbsp;&nbsp;&nbsp;<u>[Notes to Financial Statements](#i515d031fff4e4e5fa26393bcb5bc1593_19)</u> | <u>[6](#i515d031fff4e4e5fa26393bcb5bc1593_19)</u> |
| Supplemental Schedule: | |
| &nbsp;&nbsp;&nbsp;&nbsp;<u>[Form 5500 Schedule H, Part IV, Line 4i - Schedule of Assets (Held at End of Year) as of March 31, 2025](#i515d031fff4e4e5fa26393bcb5bc1593_55)</u> | <u>[11](#i515d031fff4e4e5fa26393bcb5bc1593_55)</u> |
| <u>[Signatures](#i515d031fff4e4e5fa26393bcb5bc1593_58)</u> | <u>[11](#i515d031fff4e4e5fa26393bcb5bc1593_58)</u> |

---

Note: All other schedules required by Section 2520.103-10 of the Department of Labor's Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974 have been omitted because they are not applicable.

The following exhibits are being filed herewith:

---

| | |
|:---|:---|
| **<u>Exhibit No</u>** | **<u>Description</u>** |
| <u>[23.1](wms-20250331xex231x11xk.htm)</u> | <u>[Consent of Independent Registered Public Accounting Firm](wms-20250331xex231x11xk.htm)</u> |

---

------

**REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM**

To the Audit Committee, Plan Administrator and Participants of Advanced Drainage Systems, Inc. Retirement and Stock Ownership Plan

Hilliard, Ohio

**Opinion on the Financial Statements**

We have audited the accompanying statements of net assets available for benefits of the Advanced Drainage Systems, Inc. Retirement and Stock Ownership Plan (the "Plan") as of March 31, 2025 and 2024, the related statements of changes in net assets available for benefits for the years then ended, and the related notes (collectively, the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the net assets available for benefits of the Plan as of March 31, 2025 and 2024, and the changes in net assets available for benefits for the years then ended, in conformity with accounting principles generally accepted in the United States of America.

**Basis for Opinion**

These financial statements are the responsibility of the Plan's management. Our responsibility is to express an opinion on the Plan's financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) ("PCAOB") and are required to be independent with respect to the Plan in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Plan is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits, we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Plan's internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risk of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by the Plan's management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

**Supplemental Information**

The supplemental information in the accompanying schedule of assets (held at end of year) as of March 31, 2025 has been subjected to audit procedures performed in conjunction with the audit of the Plan's financial statements. The supplemental information is presented for the purpose of additional analysis and is not a required part of the financial statements but included supplemental information required by the Department of Labor's Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. The supplemental information is the responsibility of the Plan's management. Our audit procedures included determining whether the supplemental information reconciles to the financial statements or the underlying accounting and other records, as applicable, and performing procedures to test the completeness and accuracy of the information presented in the supplemental information. In forming our opinion on the supplemental information, we evaluated whether the supplemental information, including its form and content, is presented in conformity with the Department of Labor's Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. In our opinion, the supplemental information is fairly stated, in all material respects, in relation to the financial statements as a whole.

/s/ GBQ PARTNERS LLC

We have served as the Plan's auditor since 2006.

Columbus, Ohio

September 16, 2025

------

**ADVANCED DRAINAGE SYSTEMS, INC. RETIREMENT AND STOCK OWNERSHIP PLAN**

**STATEMENTS OF NET ASSETS AVAILABLE FOR BENEFITS**

---

| | | |
|:---|:---|:---|
| | **As of March 31,** | **As of March 31,** |
| **(Amounts in thousands)** | **2025** | **2024** |
| Cash and cash equivalents | $— | $15 |
| Investments, at fair value: |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Advanced Drainage Systems, Inc. Stock Fund | 562419 | 1063815 |
| &nbsp;&nbsp;&nbsp;&nbsp;Mutual Funds | 499795 | 441708 |
| &nbsp;&nbsp;&nbsp;&nbsp;Stable Value Fund | 38363 | 40458 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total Investments | 1100577 | 1545981 |
| Employee contributions receivable | 5 | 135 |
| Employer contribution receivable | 264 | 66 |
| &nbsp;&nbsp;&nbsp;&nbsp;**Net Assets Available for Benefits** | $**1100846** | $**1546197** |

---

See accompanying notes to financial statements

------

**ADVANCED DRAINAGE SYSTEMS, INC. RETIREMENT AND STOCK OWNERSHIP PLAN**

**STATEMENTS OF CHANGES IN NET ASSETS AVAILABLE FOR BENEFITS**

---

| | | |
|:---|:---|:---|
| | **Fiscal year ended** | **Fiscal year ended** |
| **(Amounts in thousands)** | **March 31, 2025** | **March 31, 2024** |
| **Additions to Net Assets:** | | |
| &nbsp;&nbsp;&nbsp;&nbsp;Contributions: |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Rollover | $20777 | $3300 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Participant | 28222 | 25399 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Employer | 14816 | 8395 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total contributions | 63815 | 37094 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Investment (loss) income: |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Net realized and unrealized appreciation in fair value of investments |  | 702685 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Interest and dividends | 13688 | 11552 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Net investment (loss) income | 13688 | 714237 |
| &nbsp;&nbsp;&nbsp;&nbsp;**Total additions** | **77503** | **751331** |
| **Deductions from Net Assets:** |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Net realized and unrealized depreciation in fair value of investments | 329844 | **—** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Benefit payments | 192357 | 219851 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Administrative expenses | 653 | 635 |
| &nbsp;&nbsp;&nbsp;&nbsp;**Total deductions** | **522854** | **220486** |
| (Decrease) increase in Net Assets | (445351) | 530845 |
| Net Assets Available for Benefits - beginning of period | 1546197 | 1015352 |
| **Net Assets Available for Benefits - end of period** | $**1100846** | $**1546197** |

---

See accompanying notes to financial statements.

------

**ADVANCED DRAINAGE SYSTEMS, INC. RETIREMENT AND STOCK OWNERSHIP PLAN**

**NOTES TO FINANCIAL STATEMENTS**

**1.&nbsp;&nbsp;&nbsp;&nbsp;DESCRIPTION OF THE PLAN**

The following description of the Advanced Drainage Systems, Inc. Retirement and Stock Ownership Plan (the "Plan") is provided for general information purposes only. Participants should refer to the Plan document and the Plan's Summary Plan Description for a complete description of the Plan's provisions.

***General*** - The Plan is a tax-qualified defined contribution retirement plan that benefits substantially all employees of Advanced Drainage Systems, Inc. (the "Company" or "ADS") and its participating subsidiaries. The Plan is subject to the provisions of the Employee Retirement Income Security Act of 1974 as amended ("ERISA"). The Company is the Plan's sponsor and administrator under ERISA. The day-to-day operation of the Plan is handled by a three member Retirement Plan Committee appointed by the Board of Directors of the Company, and its delegates. Prior to April 1, 2022, the Company sponsored two separate tax-qualified defined contribution retirement plans (i) the Advanced Drainage Systems, Inc. Employee Stock Ownership Plan (the "ESOP"), and (ii) the Advanced Drainage Systems Retirement Plan, formerly named the Advanced Drainage Systems, Inc. Profit Sharing Retirement Plan (the "401(k) Plan"). Effective April 1, 2022, pursuant to resolutions of the Company's Board of Directors, the ESOP was merged into and with the 401(k) Plan, with the Plan thereafter having two separate components namely, an ESOP component (that qualifies as an "employee stock ownership plan" as defined in Internal Revenue Code ("Code") Section 4975(e)(7)), and a 401(k) component (that complies with the cash or deferred arrangement requirements of Code Section 401(k)).

***Contributions*** - The Plan provides for pre-tax deferral contributions by the participants through payroll deductions subject to certain limitations of Section 401(k) of the Code. Participants may also make after-tax Roth elective deferral contributions. Participants who have attained age 50 before the end of the Plan year are eligible to make catch-up contributions. Participants may also make rollover contribution amounts representing eligible rollover distributions from other employers' tax-qualified retirement plans.

The Plan includes an auto-enrollment provision whereby all newly eligible employees are automatically enrolled in the Plan unless they affirmatively elect not to participate in the Plan. All newly eligible employees are automatically enrolled at a pre-tax deferral contribution rate of 3% of eligible compensation (which automatically increases one percent per year up to a maximum of seven percent), unless the employee elects otherwise. All auto-enrollment employee contributions are invested in a designated target date fund based on the participant's age until changed by the participant.

For the plan years ended March 31, 2025 ("2025 Plan year") and March 31, 2024 ("2024 Plan year"), the Company matched 100% of the first 3% deferred by the employee and then 50% of the next 2% of eligible compensation deferred by the employee.

The Plan also provides for an annual discretionary contribution by the Company in its discretion. Participants direct the investment of their contributions into the various investment options offered by the Plan. The Plan currently offers various mutual funds, a common collective trust fund and an employer common stock fund as investment options for participants.

***Eligibility*** - Eligible employees of the Company and its participating subsidiaries (i.e., not a union employee, leased employee, Puerto Rico employee, or an independent contractor) are eligible to participate in the 401(k) component of the Plan on the first day of the month which coincides with or next follows the date the Plan's entry requirements are satisfied. The entry requirements for eligible employees are (i) the employee must be at least 18 years old, (ii) must be credited with 30 days of service, and (iii) must be employed on the entry date.

***Participant Accounts*** - Each participant's account is credited with the participant's contributions and Company matching contributions, as well as allocations of the Company's profit sharing contribution, if any, and Plan earnings. Participant accounts are charged with an allocation of administrative expenses that are paid by the Plan. Allocations are based on participant earnings, account balances, or specific participant transactions, as defined. The benefit to which a participant is entitled is the benefit that can be provided from the participant's vested account.

------

Cash dividends on shares of Company Class A Common Stock allocated to participants' Plan accounts under the ESOP portion of the Plan are passed through to such participants. Participants provide voting directions with respect to the investment funds in which their Plan accounts are invested including, without limitation, voting directions with respect to shares of Company Class A Common Stock allocated to their Plan accounts under the Plan's ESOP portion's employer stock fund.

***Vesting*** - Participants are immediately vested in their voluntary and rollover contributions plus actual earnings thereon. For purposes of matching Company contributions of Plan accounts, vesting is based on the following vesting schedule:

---

| | |
|:---|:---|
| Years of Service | Vesting Percentage |
| Less than 2 | 0% |
| 2 or greater | 100% |

---

For purposes of discretionary Company contribution portions of Plan accounts, and the ESOP portion of Plan accounts, vesting is based on the following vesting schedule:

---

| | |
|:---|:---|
| Years of Service | Vesting Percentage |
| Less than 2 | 0% |
| 2 | 20% |
| 3 | 40% |
| 4 | 60% |
| 5 | 80% |
| 6 | 100% |

---

***Distribution of Plan Accounts*** - Participants receive the amount credited to their vested Plan accounts upon retirement, disability, death or termination of employment. Participants are also eligible to receive hardship distributions of a portion of their vested Plan accounts, and participants who have attained age 59 and 1/2 may receive all or a portion of his or her account based on the vesting schedule. Distributions are paid to participants or their beneficiaries in a lump sum.

***Forfeited Accounts*** - Forfeitures of participants' unvested accounts are used to pay plan expenses and to offset Company contributions (with any amount in excess thereof allocated to participants accounts). At March 31, 2025 and 2024, forfeited non-vested accounts totaled approximately less than $0.1 million and $0.4 million, respectively. During 2025 and 2024, forfeitures of approximately $2.5 million and $6.0 million, respectively, were used to offset Company contributions and approximately $0.1 million and $0.1 million, respectively was used to pay administrative expenses.

Subsequent to March 31, 2025, the Plan Sponsor used approximately $0.3 million in forfeitures to reduce the 2025 true-up Company contributions due to the Plan as of March 31, 2025, the plan year end.

**2.&nbsp;&nbsp;&nbsp;&nbsp;SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES**

***Basis of Accounting*** - The financial statements of the Plan are prepared on the accrual basis of accounting.

***Use of Estimates*** - The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, and changes therein, and disclosure of contingent assets and liabilities. Actual results could differ from those estimates.

***Investment Valuation and Income Recognition*** - The Plan's investments are reported at fair value. Fair value is a price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market

participants at the measurement date. For additional disclosure regarding fair value of investments, see the Fair Value Measurements footnote herein.

------

Purchases and sales of securities are recorded on a trade-date basis. Interest income is recorded on the accrual basis. Dividends are recorded on the ex-dividend date. Net appreciation (depreciation) includes the Plan's gains and losses on investments bought and sold, as well as held during the year.

***Administrative Expenses*** - During the 2025 and 2024 plan years, the Plan Sponsor paid Plan administrative costs of $0.7 million and $0.3 million, respectively, and the Plan paid its remaining administrative expenses including audit, consulting, trustee and recordkeeping fees of approximately $0.6 million and $0.6 million, respectively.

***Payment of Benefits*** - Benefits are recorded when paid.

**3.&nbsp;&nbsp;&nbsp;&nbsp;EMPLOYER STOCK FUND**

Participants can elect to invest in the Plan's employer stock fund consisting of Company Class A Common Stock. The Plan's employer stock fund may also hold cash or cash equivalents as necessary to satisfy the obligations of the fund. Participants may not allocate more than 20% of their future contributions to the employer stock fund, and may not elect to invest their Plan accounts in the Plan's employer stock fund at any time a participant's Plan account exceeds 20% of the value of the participant's total assets allocated to his or her Plan account.

**4.&nbsp;&nbsp;&nbsp;&nbsp;FAIR VALUE MEASUREMENTS**

GAAP established a fair value hierarchy that prioritizes the inputs to measure the fair value of the assets or liabilities being measured. Fair value is defined as the exchange value that would be received on the measurement date to sell an asset or to value the amount paid to transfer a liability in the principal or most advantageous market available to the entity in an orderly transaction between market participants. The three levels of the fair value hierarchy are as follows:

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| | |
|:---|:---|
| *Level 1:* | Inputs are unadjusted quoted market prices in active markets for identical assets or liabilities that the entity has the ability to access at the measurement date. Level 1 inputs provide the most reliable measure of fair value as of the measurement date. |
| *Level 2:* | Inputs are based on significant observable inputs, including unadjusted quoted market prices for similar assets and liabilities in active markets, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or inputs other than quoted prices that are observable for the asset or liability. |
| *Level 3:* | Inputs are significant and unobservable inputs for the asset or liability. |

---

The following is a description of the valuation methodologies used for assets measured at fair value. There have been no changes in the methodologies used at March 31, 2025 or 2024.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*• Mutual Funds and ADS Common Stock:* Valued at the net asset value of shares held by the Plan at year-end.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;• *Common Collective Trust Fund:* Valued at the net asset value ("NAV") provided by the administrator of the fund. Issues and redemptions of units are recorded upon receipt of unit holder's instructions based on the determined NAV per unit, which is determined daily. The NAV is used as a practical expedient to estimate fair value. The NAV is based on the fair value of the underlying investments held by the fund less its liabilities. This practical expedient is not used when it is determined to be probable that the fund will sell the investment for an amount different than the reported NAV. For these funds, there are no unfunded commitments, redemption restrictions and participants can transact daily.

The preceding methods described may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, although the Plan believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date.

------

The following tables sets forth by level, within the fair value hierarchy, the Plan's assets at fair value as of March 31, 2025 and 2024. Classification within the fair value hierarchy table is based on the lowest level of any input that is significant to the fair value measurement.

**Assets at Fair Value as of March 31, 2025:**

---

| | | | | |
|:---|:---|:---|:---|:---|
| **(Amounts in thousands)** | **<u>Level 1</u>** | **<u>Level 2</u>** | **<u>Level 3</u>** | **<u>Total</u>** |
| *Investments in the fair value hierarchy:* |  |  |  |  |
| Mutual Funds | $499795 | $— | $— | $499795 |
| ADS Common Stock | 562419 |  |  | 562419 |
| Total investments in the fair value hierarchy | 1062214 |  |  | 1062214 |
| Common collective trust fund measured at net asset value<sup>1</sup> |  |  |  | 38363 |
| **Total assets at fair value** | $**1062214** | $**—** | $**—** | $**1100577** |

---

**Assets at Fair Value as of March 31, 2024:**

---

| | | | | |
|:---|:---|:---|:---|:---|
| **(Amounts in thousands)** | **<u>Level 1</u>** | **<u>Level 2</u>** | **<u>Level 3</u>** | **<u>Total</u>** |
| *Investments in the fair value hierarchy:* |  |  |  |  |
| Mutual Funds | $441708 | $— | $— | $441708 |
| ADS Common Stock | 1063815 |  |  | 1063815 |
| Total investments in the fair value hierarchy | 1505523 |  |  | 1505523 |
| Common collective trust fund measured at net asset value<sup>1</sup> |  |  |  | 40458 |
| **Total assets at fair value** | $**1505523** | $**—** | $**—** | $**1545981** |

---

1.&nbsp;&nbsp;&nbsp;&nbsp;In accordance with Subtopic 820-10, certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the line items presented in the statements of net assets available for benefits.

**5.&nbsp;&nbsp;&nbsp;&nbsp;PARTY-IN-INTEREST TRANSACTIONS**

Principal Trust Company is the Plan's trustee and its affiliate, Principal Finance Group, is the Plan's recordkeeper. The Plan has a common collective trust with Principal Trust Company, and, therefore, this transaction qualifies as a party-in-interest transaction. In 2025 and 2024, the Plan also used various accounting and consulting firms to assist with Plan compliance and administration. Fees paid to parties in interest totaled approximately $0.6 million and $0.6 million, respectively, for the 2025 and 2024 Plan years.

**6.&nbsp;&nbsp;&nbsp;&nbsp;RISKS AND UNCERTAINTIES**

The Plan invests in various investment securities. Investment securities are exposed to various risks such as interest rate, market and credit risks. Due to the level of risk associated with certain investment securities, it is at least reasonably possible that changes in the values of investment securities will occur in the near-term and that such a change could materially affect participants' account balances and the amounts reported in the accompanying 2025 statement of net assets available for benefits.

**7.&nbsp;&nbsp;&nbsp;&nbsp;INCOME TAX STATUS**

The Company has adopted a Principal Financial Group ESOP/KSOP Pre-Approved Plan document as the Plan's amended and restated document effective April 1, 2022, which is a volume submitter document with respect to which Principal Financial Group received a favorable opinion letter from the Internal Revenue Service ("IRS") that such Plan document complied with the applicable tax-qualification requirements of the Code. Principal Financial Group has advised the Company that the Plan's document is covered by the IRS opinion letter issued to Principal Financial Group and that the Plan is currently being administered in compliance with the applicable requirements of the Code and in compliance with the provisions of the Plan.

------

GAAP requires plan management to evaluate tax positions taken by the Plan and recognize a tax liability (or asset) if the Plan has taken an uncertain position that more likely than not would not be sustained upon examination by the IRS. The plan administrator has analyzed the tax positions taken by the Plan, and has concluded that as of March 31, 2025, there are no uncertain positions taken or expected to be taken that would require recognition of a liability (or asset) or disclosure in the financial statements. The Plan is subject to routine audits by taking jurisdictions; however there are currently no audits for any tax periods in process.

**8.&nbsp;&nbsp;&nbsp;&nbsp;PLAN TERMINATION**

Although it has not expressed any intent to do so, the Company has the right under the Plan to discontinue its contributions at any time and to terminate the Plan subject to the provisions of the Code and ERISA. In the event of Plan termination, participants become 100% vested in their unvested Plan accounts. Distributions can be made in cash or securities. All non-cash distributions will be valued at fair market value at the date of distribution.

**9. PLAN AMENDMENT**

During fiscal 2025, the Plan was amended to include Orenco Systems, Inc. ("Orenco") as a predecessor employer and the former employees of Orenco became eligible to participate in the Plan on January 1, 2025.

**10.&nbsp;&nbsp;&nbsp;&nbsp;SUBSEQUENT EVENTS**

The Plan has evaluated subsequent events through the date of the Independent Auditor's Report, the date the financial statements were available to be issued.

------

**ADVANCED DRAINAGE SYSTEMS, INC.**

**RETIREMENT AND STOCK OWNERSHIP PLAN**

**EIN 51-0105665 - PLAN 001**

**Schedule H, Line 4i - Schedule of Assets (Held at End of Year)**

**March 31, 2025**

**Amounts in Thousands**

---

| | | | |
|:---|:---|:---|:---|
| (a) | Identity of Issue, Borrower, Lessor or Similar Party | Shares | Current Value |
|  | Common Stock: |  |  |
| \* | &nbsp;&nbsp;Advanced Drainage Systems, Inc. Class A Common Stock | 5176 | $562419 |
|  | Common Collective Trusts: |  |  |
| \* | &nbsp;&nbsp;Morley Capital Management Principal Stable Value Z Fund | 1498 | 38363 |
|  |  |  | 600782 |
|  | Mutual Funds: |  |  |
|  | &nbsp;&nbsp;Fidelity 500 Index Fund | 443 | 86509 |
|  | &nbsp;&nbsp;Vanguard Target Retirement 2030 Investment Fund | 1494 | 56702 |
|  | &nbsp;&nbsp;Vanguard Target Retirement 2035 Investment Fund | 2790 | 66923 |
|  | &nbsp;&nbsp;Vanguard Target Retirement 2040 Investment Fund | 1151 | 49650 |
|  | &nbsp;&nbsp;Vanguard Target Retirement 2045 Investment Fund | 1551 | 45836 |
|  | &nbsp;&nbsp;Vanguard Target Retirement 2050 Investment Fund | 721 | 35746 |
|  | &nbsp;&nbsp;Vanguard Target Retirement 2055 Investment Fund | 444 | 24533 |
|  | &nbsp;&nbsp;Vanguard Target Retirement 2025 Investment Fund | 978 | 18404 |
|  | &nbsp;&nbsp;JP Morgan US Equity Fund | 960 | 22623 |
|  | &nbsp;&nbsp;Fidelity Extended Market Index Fund | 154 | 12751 |
|  | &nbsp;&nbsp;Vanguard Target Retirement 2060 Investment Fund | 260 | 13251 |
|  | &nbsp;&nbsp;Vanguard Target Retirement Income Investment Fund | 652 | 8609 |
|  | &nbsp;&nbsp;Dodge & Cox Income Fund | 873 | 11012 |
|  | &nbsp;&nbsp;Fidelity International Index Fund | 171 | 8761 |
|  | &nbsp;&nbsp;Fidelity US Bond Index Fund | 796 | 8284 |
|  | &nbsp;&nbsp;Vanguard Target Retirement 2020 Investment Fund | 140 | 3748 |
|  | &nbsp;&nbsp;Vanguard Target Retirement 2070 Investment Fund | 227 | 6022 |
|  | &nbsp;&nbsp;Fidelity Stock Selector Small Cap Fund | 204 | 6942 |
|  | &nbsp;&nbsp;Vanguard Target Retirement 2065 Investment Fund | 203 | 6789 |
|  | &nbsp;&nbsp;EuroPacific Growth Fund | 76 | 4180 |
|  | &nbsp;&nbsp;DWS RREEF Real Assets Fund | 208 | 2520 |
|  |  |  | $1100577 |

---

\*&nbsp;&nbsp;&nbsp;&nbsp;Denotes party-in-interest

**SIGNATURES**

Pursuant to the requirements of the Securities Exchange Act of 1934, the trustees (or other persons who administer the employee benefit plan) have duly caused this annual report to be signed on its behalf by the undersigned hereunto duly authorized.

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| | | |
|:---|:---|:---|
| | ADVANCED DRAINAGE SYSTEMS, INC. RETIREMENT AND STOCK OWNERSHIP PLAN | ADVANCED DRAINAGE SYSTEMS, INC. RETIREMENT AND STOCK OWNERSHIP PLAN |
| Date: September 16, 2025 | By: | /s/ Kevin C. Talley |
|  | Name: | Kevin C. Talley |
|  | Title: | EVP, Chief Administrative Officer and KSOP Committee Member |

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## Exhibit 23.1

**Exhibit 23.1**

**CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM**

Advanced Drainage Systems, Inc. Retirement and Stock Ownership Plan<br>Hilliard, Ohio

We hereby consent to the incorporation by reference in the Registration Statement on Form S-8 (333-197732) of Advanced Drainage Systems, Inc. of our report dated September 16, 2025, relating to the financial statements and supplemental schedule of the Advanced Drainage Systems, Inc. Retirement and Stock Ownership Plan which appear in this Form 11-K for the year ended March 31, 2025.

/s/ GBQ PARTNERS LLC<br>Columbus, Ohio

September 16, 2025

<br>