NASA has released the final text for the 2026 Astrophysics Small Explorer (APSMEX) opportunity, available for download via NSPIRES. A mandatory Notice of Intent and a virtual preproposal conference are required prior to the proposal due date. All questions must be submitted via email to the listed contacts with "APSMEX26" in the subject line. No specific budget amount or performance location is specified in this description. Interested parties should monitor the solicitation sites for amendments and updates.