When you leave, two clocks start
Your plan window for exercising vested options (often 90 days) is one clock. The federal 3-month ISO tax clock is the second. Sometimes they line up. Sometimes they don't.
Quick check
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Don't miss the clock
When does my exercise window close?
5 min · 5 steps
US-focused. Last reviewed April 2026Tax math follows IRS Pub 525, §422, §1202 and current AMT rules. See sources in the methodology note.
Educational only. Not tax, legal, or financial advice. Talk to a qualified advisor.