What it is
FSA contributions come out of pay pre-tax. The balance is paid from contributions, so unspent funds at the end of the plan year are forfeited, subject to a carryover option or a 2.5-month grace period where the plan offers one. Health FSA contributions stop on your last day.
What to do about it: Order eligible items before your last day and keep receipts. Post-separation claims under a COBRA-eligible FSA have a defined route: document it before you leave.
Plain-language description of US practice, not legal, tax, or financial advice. The paired guide carries the citations, dates, and thresholds; the state pages carry the local windows.