ADVANCED ENERGY INDUSTRIES INC

On October 29, 2026, the Compensation Committee of the Company’s Board of Directors approved an amendment to the outstanding performance stock unit awards (the “PSU Awards”). The amendment removed the cap that limited the earned value of the relative total shareholder return (“rTSR”) performance metric component to five times the grant-date value. The amendment did not modify any other terms of the PSU Awards, including the applicable service periods or the limitation that the maximum payout under each PSU Award may not exceed 200% of the target shares established by the Compensation Committee. As a result of the modification, we expect to recognize approximately $10.0 million of additional stock-based compensation expense, of which approximately $4.0 million is expected to be recognized in the fourth quarter of 2026, with the remainder recognized over the remaining service periods of the respective grants. The shares earned by the executives pursuant to the amended PSU Awards will be determined upon achievement of the applicable performance conditions at the end of the measurement period.

Rule 10b5-1 Trading Arrangements

During the three months ended September 30, 2026, except as described below, none of our directors or Section 16 officers adopted orterminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement” (as each term is defined in Item 408 of Regulation S-K). The following table summarizes the terms of the Rule 10b5-1 trading arrangements adopted:

(1) At the Company's discretion, executives may be required to satisfy tax withholding obligations through cash payments or sell-to-cover transactions rather than share withholding. This Rule 10b5-1 trading arrangement provides for eligible “sell-to-cover transactions” (as described in Rule 10b5-1(c)(1)(ii)(D)(3) under the Exchange Act) only as are necessary to satisfy tax withholding obligations arising from the vesting of restricted stock units and PSUs. The number of shares that will be sold under this Rule 10b5-1 trading arrangement is not currently determinable as the number will vary based on the market price of our common stock and the satisfaction of certain applicable performance goals. The arrangement will remain in effect until the earlier of (a) termination of employment with the Company or (b) execution and delivery of an agreement to terminate.

(2) This Rule 10b5-1 trading arrangement also provides for termination prior to the above-listed expiration date following the occurrence of certain events, such as public announcement of a tender offer, exchange offer, or certain merger and acquisition, reorganization, or recapitalization transactions or the bankruptcy, insolvency, or death of the adopting person.

(3) The aggregate number of shares available for sale under Mr. Colpitts's Rule 10b5-1 trading arrangement is not yet determinable because the trading arrangement relates to shares issuable pursuant to unvested restricted stock units and PSUs, which are subject to tax withholding obligations that arise in connection with the vesting and settlement of such awards and, with respect to PSUs, the satisfaction of certain applicable performance goals.