Five9, Inc.

Rule 10b5-1 Plans

During the fiscal quarter ended March 31, 2026, none of the Company’s directors and officers adopted, modified, orterminated a Rule 10b5-1 trading arrangement or a non-Rule 10b5-1 trading arrangement.

Costs Associated with Exit or Disposal Activities

We are reporting the following information for the purpose of providing the disclosure required under Form 8-K Item 2.05 “Costs Associated with Exit or Disposal Activities.”

Corporate Headquarters Consolidation

On April 27, 2026, management initiated a plan to consolidate our corporate headquarters in San Ramon, California by reducing the facility space we occupy from two floors to a single floor by May 2026 (the “Plan”). The Plan will result in excess facility space that we intend to sublease. Consequently, we expect to record an impairment loss on our operating lease right-of-use assets and related leasehold improvements of between $8.0 to $9.0 million in the second quarter of 2026. This impairment loss that we expect to incur in connection with the Plan will be estimated based on a review and analysis of real estate market conditions, our projected sublease income and sublease commencement assumptions. Actual amounts, and the timing of the impairment loss, may differ materially from our current and future estimates. We may also incur other charges not currently contemplated due to unanticipated events that may occur, including in connection with the implementation of the Plan. The impairment loss will be reflected in our operating expenses in our condensed consolidated statements of income. The $8.0 million to $9.0 million impairment loss associated with the Plan were included in the second quarter of 2026 and full year 2026 GAAP net income per share guidance issued on April 30, 2026. We intend to exclude these costs from our non-GAAP financial measures.