Updated August 7, 2026. Quick answer: a layoff starts several clocks at once, and they do not run from the same date. The release has one deadline, the revocation window is a second, COBRA runs from the later of two dates, and the rule of 55 turns on the calendar year rather than your birthday. Enter your separation date and get the actual calendar.
The calculator
The four clocks, and what each one is
The release deadline. Federal law requires that you get at least 21 days to consider a waiver of age claims — and at least 45 days if the offer is part of a group layoff or exit-incentive program. That is a floor, not a ceiling; an employer may give you longer.
The revocation window — the one people do not know they have. After signing, you get at least 7 days to revoke, and the statute is explicit that the agreement “shall not become effective or enforceable until the revocation period has expired”. Signing is not the end of the decision.
COBRA runs from the later of two dates. The election period is at least 60 days and ends “not earlier than 60 days after the later of” the date coverage ended or the date your election notice arrived. If your notice came late, your deadline is later than 60 days from your last day — and most calendars get this wrong.
The rule of 55 turns on the year, not the date. The 401(k) early-withdrawal exception needs separation in or after the calendar year you turn 55. Someone laid off in November who turns 55 the following January does not qualify; someone laid off in January who turns 55 in December does. It also applies only to that employer’s plan.
Each clock above has a page that works through it properly: the release and revocation windows, the 401(k) loan-offset deadline, the FSA run-out clock, and the retiree-medical eligibility cliff, which has no statutory deadline at all — it is decided by your separation date. The order to take them in is the decision order.
If the package itself is the decision
The calendar tells you when. Whether to take a lump sum, when to start a pension, and what a deferred-comp distribution does to your tax year are separate questions with real money in them.
What to ask an advisor about a severance package is the version of that conversation worth having before the release deadline, not after.
Sources
Release and revocation windows: 29 U.S.C. §626(f)(1). COBRA election period: 29 U.S.C. §1165(a)(1). Both read 7 August 2026. Rule of 55: IRC §72(t)(2)(A)(v). This is general information about statutory deadlines, not legal advice on your agreement — and your own documents may give you longer than the statutory floor.