Form 4 for WMS ADVANCED DRAINAGE SYSTEMS, INC.

Accepted 2026-05-21 18:36:41 ET · period of report 2026-05-19 · accession 0001193125-26-235056 · SEC index · Original document

Summary rows

Aggregated the way they appear in lists: one row per insider, transaction code and security table.

X	Filed	Traded	Ticker	Insider	Title	Type	Price	Qty	Owned	ΔOwn	Value
M	2026-05-21 18:36	2026-05-19+	WMS	Cottrill Scott A	EVP, CFO AND Sec	F - Tax	$134.47	-616	98.5K	-0.6%	-$82.8K
	2026-05-21 18:36	2026-05-20	WMS	Cottrill Scott A	EVP, CFO AND Sec	A - Grant	$0.00	+10.1K	108.6K	+10%	$0

Purchase Sale Sale after option exercise All abbreviations

#	Table	Security	Date	Code	A/D	Shares	Price	Owned after	Own	Exercise / expiry	Underlying	Footnotes
1	Common	Common Stock	2026-05-19	F	D	277	$131.59	98,876	D	—	—	(F1) Represents shares withheld to satisfy Reporting Person's tax obligations in connection with the vesting of shares of restricted common stock of the Issuer. (F2) Includes 89 shares of common stock acquired under the Advanced Drainage Systems, Inc. Employee Stock Purchase Plan, exempt under Rule 16b-3(c).
2	Common	Common Stock	2026-05-20	F	D	339	$136.83	98,537	D	—	—	(F1) Represents shares withheld to satisfy Reporting Person's tax obligations in connection with the vesting of shares of restricted common stock of the Issuer.
3	Common	Common Stock	2026-05-20	A	A	10,075	$0.00	108,612	D	—	—	(F3) Reflects grant of performance-based units, originally granted pursuant to the Issuer's 2017 Omnibus Incentive Plan, earned after the Issuer determined that certain performance goals for the performance period ended March 31, 2026 had been met. Total includes dividend equivalents in the amount of 130 shares, which dividend equivalents are settled in common stock.