Employee Benefit Plans	12 Months Ended
Jun. 30, 2026
Retirement Benefits [Abstract]
Employee Benefit Plans	16. Employee Benefit Plans 401(k) Retirement Plan All U.S. employees who meet certain eligibility requirements can participate in Covista’s 401(k) Retirement Plan. Covista makes a matching employer contribution into the 401(k) Retirement Plan of 100% up to the first 6% of the participant’s eligible compensation. Expense for the matching employer contributions under the plan was $25.2 million, $21.9 million, and $19.7 million for the years ended June 30, 2026, 2025, and 2024, respectively. Colleague Stock Purchase Plan Under provisions of Covista’s current Colleague Stock Purchase Plan, any eligible employee may authorize Covista to withhold up to $25,000 of annual wages to purchase common stock of Covista. Covista implemented a new Colleague Stock Purchase Plan approved by stockholders at Covista’s annual meeting of stockholders held on November 6, 2019 which allows for the issuance of 500,000 shares. Employees can purchase Covista’s common stock at 90% of the prevailing market price on the purchase date. Covista pays all brokerage commissions and administrative fees associated with the plan. These expenses were not material for the years ended June 30, 2026, 2025, and 2024. Total shares issued under the plans were 16,425, 17,148, and 19,666 for the years ended June 30, 2026, 2025, and 2024, respectively. These plans are intended to qualify as an “employee stock purchase plan” within the meaning of Section 423 of the Internal Revenue Code. Covista reissues treasury shares to satisfy employee share purchases under this plan. Nonqualified Deferred Compensation Plan Covista has a nonqualified deferred compensation (“NDCP”) plan for highly compensated employees and its Board members. The plan allows participants to make tax-deferred contributions that cannot be made under the 401(k) Retirement Plan because of Internal Revenue Service limitations. The plan permits the deferral of up to 50% of a participant’s salary and up to 100% of a participant’s bonus or board fee. Covista matches up to 6% of the total eligible compensation of participants who make contributions under the plan. Amounts contributed and deferred under the plan are credited or charged with the performance of investment options offered under the plan as elected by the participants. The participant’s “investments” are in a hypothetical portfolio of investments which are tracked by an administrator. Total liabilities under the NDCP plan included in accrued liabilities on the Consolidated Balance Sheets as of June 30, 2026 and 2025 were $15.7 million and $13.5 million, respectively. The increase or decrease in the fair value of the liabilities under the NDCP plan is included in student services and administrative expense in the Consolidated Statements of Income. We have elected to fund our NDCP plan obligations through a rabbi trust. The rabbi trust is subject to creditor claims in the event of insolvency, but the assets held in the rabbi trust are not available for general corporate purposes. Amounts in the rabbi trust are placed in investments whose performance is generally consistent with the investments chosen by participants under their NDCP plan accounts, which are designated as trading securities and carried at fair value. The fair value of the investments in the rabbi trust included in prepaid expenses and other current assets on the Consolidated Balance Sheets as of June 30, 2026 and 2025 was $15.6 million and $12.8 million, respectively. We record trading gains and losses in other income, net in the Consolidated Statements of Income.

Employee Benefit Plans

12 Months Ended

Jun. 30, 2026

16. Employee Benefit Plans

401(k) Retirement Plan

All U.S. employees who meet certain eligibility requirements can participate in Covista’s 401(k) Retirement Plan. Covista makes a matching employer contribution into the 401(k) Retirement Plan of 100% up to the first 6% of the participant’s eligible compensation. Expense for the matching employer contributions under the plan was $25.2 million, $21.9 million, and $19.7 million for the years ended June 30, 2026, 2025, and 2024, respectively.

Colleague Stock Purchase Plan

Under provisions of Covista’s current Colleague Stock Purchase Plan, any eligible employee may authorize Covista to withhold up to $25,000 of annual wages to purchase common stock of Covista. Covista implemented a new Colleague Stock Purchase Plan approved by stockholders at Covista’s annual meeting of stockholders held on November 6, 2019 which allows for the issuance of 500,000 shares. Employees can purchase Covista’s common stock at 90% of the prevailing market price on the purchase date. Covista pays all brokerage commissions and administrative fees associated with the plan. These expenses were not material for the years ended June 30, 2026, 2025, and 2024. Total shares issued under the plans were 16,425, 17,148, and 19,666 for the years ended June 30, 2026, 2025, and 2024, respectively. These plans are intended to qualify as an “employee stock purchase plan” within the meaning of Section 423 of the Internal Revenue Code. Covista reissues treasury shares to satisfy employee share purchases under this plan.

Nonqualified Deferred Compensation Plan

Covista has a nonqualified deferred compensation (“NDCP”) plan for highly compensated employees and its Board members. The plan allows participants to make tax-deferred contributions that cannot be made under the 401(k) Retirement Plan because of Internal Revenue Service limitations. The plan permits the deferral of up to 50% of a participant’s salary and up to 100% of a participant’s bonus or board fee. Covista matches up to 6% of the total eligible compensation of

participants who make contributions under the plan. Amounts contributed and deferred under the plan are credited or charged with the performance of investment options offered under the plan as elected by the participants. The participant’s “investments” are in a hypothetical portfolio of investments which are tracked by an administrator. Total liabilities under the NDCP plan included in accrued liabilities on the Consolidated Balance Sheets as of June 30, 2026 and 2025 were $15.7 million and $13.5 million, respectively. The increase or decrease in the fair value of the liabilities under the NDCP plan is included in student services and administrative expense in the Consolidated Statements of Income.

We have elected to fund our NDCP plan obligations through a rabbi trust. The rabbi trust is subject to creditor claims in the event of insolvency, but the assets held in the rabbi trust are not available for general corporate purposes. Amounts in the rabbi trust are placed in investments whose performance is generally consistent with the investments chosen by participants under their NDCP plan accounts, which are designated as trading securities and carried at fair value. The fair value of the investments in the rabbi trust included in prepaid expenses and other current assets on the Consolidated Balance Sheets as of June 30, 2026 and 2025 was $15.6 million and $12.8 million, respectively. We record trading gains and losses in other income, net in the Consolidated Statements of Income.