By federal law (Internal Revenue Code § 6502), the IRS has 10 years from the date your tax was assessed to collect it. After that, the debt is legally uncollectible. The expiration date is called the CSED — Collection Statute Expiration Date.
But the 10-year clock isn’t continuous. Several events toll (pause) it. Get those wrong and you’ll think you’re closer to the finish line than you actually are.
CSED Calculator
Tolling events (optional)
Add the duration in days for any event that paused your clock. Most people have zero. If you've never filed an OIC, never been in bankruptcy, never had a CDP hearing, and have lived in the US continuously — leave these blank.
Educational estimate. Your actual CSED is set by the IRS and can be confirmed by ordering an IRS Account Transcript at IRS.gov. Look for the CSED line or call 1-800-829-1040 and ask for "CSEDs on each tax period."
What “assessment date” means
Your tax debt has an assessment date — not the same as the year the tax was for, and not the same as the date you filed.
- If you filed and the IRS accepted the return, assessment is usually 3–6 weeks after filing.
- If you didn’t file and the IRS filed a Substitute For Return (SFR), assessment is the date they entered the SFR.
- If the IRS audited you and added tax, the audit deficiency has its own assessment date — different from the original return.
Each tax year has its own CSED. A balance from your 2017 return and a balance from your 2020 return have different expiration dates. Always treat them separately.
The single most useful document is your IRS Account Transcript. It lists every assessment, every payment, every tolling event, and (in some cases) the calculated CSED. Get one free at IRS.gov/transcript.
The events that pause the clock
The IRS calls these “tolling events.” When one is in effect, the CSED clock stops. When the event ends, the clock starts again — and several events also tack on extra time beyond just the duration.
| Event | Tolling period | Bonus time |
|---|---|---|
| Offer in Compromise pending | While pending | + 30 days after rejection/withdrawal |
| CDP hearing pending | While pending | + 90 days after determination |
| Bankruptcy filing | While case open | + 6 months after discharge/dismissal |
| Continuous absence from US > 6 months | Duration of absence | None |
| Innocent spouse claim pending | While pending | + 60 days after determination |
| Pending installment agreement request | While pending | + 30 days after rejection |
| Taxpayer Assistance Order | While pending | None |
| Combat zone deployment | Duration + 180 days | + 180 days |
Tolling events stack. If you filed an OIC that was rejected, then filed bankruptcy, then went through a CDP hearing — all three pause the clock independently.
Why this matters strategically
If your CSED is far away (5+ years out), you have time to use any program — OIC, IA, CNC, partial-pay IA — without much risk.
If your CSED is close (2–3 years out), your best move is often a partial-pay installment agreement (PPIA) or Currently Not Collectible (CNC) status. You make small or no payments, the clock keeps running, and the balance expires. You don’t pay it.
If your CSED is inside 18 months, an Offer in Compromise is usually the wrong move — it tolls the clock and the IRS knows it. They may wait you out and reject the offer late, leaving you worse off than if you had done nothing.
What this calculator can’t see
- The IRS’s exact tolling computation (their internal records are authoritative; this is an estimate).
- Whether a 1980-1990s amendment to your debt resets the clock (rare, complex).
- Whether you signed a CSED waiver as part of an old installment agreement (the IRS stopped doing this in 2002, but pre-2002 waivers can still extend a CSED).
If your CSED matters financially, pay a tax pro to read your transcripts. It’s typically a 1–2 hour engagement and the answer is binary: either the debt expires soon or it doesn’t.