IRS Collection Statute Expiration (CSED): Tolling and Extensions

The IRS collection statute expiration date, known as the CSED, is the deadline by which the IRS must collect an assessed tax debt. Under Internal Revenue Code Section 6502, that deadline is generally ten years from the date the liability was formally assessed.¹ Once the CSED passes, the debt becomes legally unenforceable and the IRS must stop collecting. The complication is that many ordinary taxpayer actions pause the clock, and a few can push it out well beyond ten years.

When the Ten-Year Clock Starts

The countdown does not begin when you file your return or when the April deadline passes. It begins on the assessment date, the day the IRS formally records your liability in its system. Internally, the IRS calls this the “23C date.”² For most filers, assessment happens shortly after the IRS processes a return.

Each assessment carries its own CSED. That matters because a single tax year can generate more than one:

If you never filed and the IRS prepared a substitute return for you, that assessment starts its own ten-year clock.³
If you filed an amended return (Form 1040-X) that increased your balance, the added tax gets its own CSED.³
If an audit produced additional tax later, that later assessment has a separate ten-year window while the original assessment keeps its own.

You could easily have three or four CSEDs running at once for the same tax year. Each has to be tracked separately.

What Happens When the CSED Passes

Once ten years have run (adjusted for any tolling), the IRS loses its authority to enforce the debt. No bank levies, no wage garnishments, and no refund offsets against that old balance. Any federal tax lien tied to the expired debt must be released, and the statute requires the IRS to issue a certificate of release within 30 days of determining the liability is unenforceable.⁴

In practice, releases don’t always happen automatically. If a lien lingers on your credit report or in property records after your CSED, you may need to contact the IRS and ask for the release in writing.

Actions That Pause the Clock

Certain events freeze the ten-year countdown through a process called tolling. While a tolling event is active, no time runs on the CSED. When the event ends, the clock resumes and often carries an added grace period on top. Many of these events are initiated by the taxpayer, which means asking for relief can quietly buy the IRS more collection time.

Offers in Compromise

Submitting an Offer in Compromise pauses the clock from the moment the IRS accepts the offer for processing through its evaluation of the proposal. If the IRS rejects the offer, the suspension continues for an additional 30 days, and if you appeal within that window, the pause runs through the entire appeal.⁵ Multiple offers over several years can add more than a year of collection time, even if none are accepted.

Installment Agreements

Requesting a payment plan under Section 6159 suspends the CSED from the date of the request until the IRS acts on it. A rejection triggers an additional 30-day suspension, and the same 30-day extension follows the termination of an existing agreement.⁶ An appeal filed within that 30-day window extends the pause through the appeal.⁵

Collection Due Process Hearings

When the IRS sends a notice of intent to levy, you can request a Collection Due Process hearing. That request suspends the CSED from the day the IRS receives it until a final determination issues. The collection period also can’t expire until at least 90 days after that final determination, even if the original clock would have run out sooner.⁷ If the matter goes to Tax Court, the pause can easily last more than a year.

Innocent Spouse Relief

Filing for innocent spouse relief pauses the collection clock on the requesting spouse’s liability. The suspension runs from the filing date through 60 days after the earliest of: a filed waiver, the expiration of the 90-day Tax Court petition period, or a final Tax Court decision.⁸ Many joint filers don’t realize that seeking relief from a shared liability actually lengthens the time the IRS has to collect from the spouse who asked for it.

Bankruptcy

A bankruptcy filing triggers an automatic stay that blocks collection.⁹ The CSED freezes for the whole case plus six months after it ends.¹⁰ A Chapter 13 case running three to five years can push the CSED out by nearly six years total. That is worth weighing before filing, especially if your CSED is close.

Living Outside the United States

If you’re continuously outside the country for six months or more, the clock stops for the whole time you’re gone. And if the remaining CSED would otherwise expire within six months of your return, it’s extended to six months after you’re back.¹⁰¹¹

Combat Zone Service

Service in a designated combat zone suspends the CSED for the length of the deployment plus at least 180 days after the service member’s last day in the zone.¹²

Two Ways the Deadline Can Grow Beyond Ten Years

The tolling events above pause an existing ten-year window. Two other mechanisms can extend the deadline far past ten years by design.

Form 900 Waivers on Partial Payment Installment Agreements

When a taxpayer qualifies for a Partial Payment Installment Agreement, the IRS may ask them to sign Form 900, a Tax Collection Waiver that voluntarily extends the CSED. The extension is capped at five years beyond the original expiration date, plus up to one additional year for administrative actions. The IRS can only request the waiver when the agreement is first set up, not during later reviews.¹³

You have the right to refuse. Refusal isn’t free, though: the IRS will recommend rejecting the installment agreement and refer the case for independent review.¹³ Waivers aren’t required for every Partial Payment Installment Agreement. They’re typically requested when there’s a specific asset the taxpayer will receive after the current CSED expires and collecting on that asset later would beat liquidating current assets. If ongoing monthly payments are the only realistic source of collection, a waiver generally isn’t required.

Suits to Reduce Tax to Judgment

The IRS can sue in federal court to convert your assessment into a court judgment. If it files suit before your CSED expires, the collection period is extended until the judgment is satisfied or becomes unenforceable.¹ Under federal law, a judgment lien lasts 20 years and can be renewed for another 20 years with court approval.¹⁴

This is the most dramatic extension possible. A balance approaching its ten-year expiration can become a 20-year judgment lien, renewable for another 20. The IRS doesn’t take this route for every case; it tends to be reserved for large liabilities or taxpayers with substantial assets. Internally, the IRS records the change by posting Transaction Code 550 with a new CSED set 20 years from the judgment date.¹⁵

How to Find Your Own CSED

Calculating your actual CSED requires two pieces of information: when each assessment was made and whether any tolling events have run since. Both are on your IRS account transcript.

Getting the Right Transcript

The quickest option is the IRS online account, which lets you view and download transcripts immediately.¹⁶ If you can’t use the online tool, Form 4506-T requests a mailed copy for the years you specify.¹⁷ Ask for the Account Transcript, not the Return Transcript. The account transcript shows assessments, payments, and status changes.

Transaction Codes That Matter

Transcripts use numbered transaction codes to record events. For CSED purposes, watch for these:

TC 150 is the initial return assessment. Its date is usually your CSED starting point.¹⁸
TC 480 signals a pending Offer in Compromise, meaning tolling is active.
TC 520 is a broad tolling code covering bankruptcy, CDP appeals, and court litigation, with closing codes identifying the specific cause.
TC 971 with action codes 043, 063, or 163 indicates an installment agreement pending, rejected, or under appeal.
TC 971 AC 065 indicates a pending innocent spouse claim.
TC 500 marks combat zone or contingency operation suspension.
TC 550 is a direct correction or extension of the CSED, including Form 900 waivers (definer code 01) and court judgments (definer code 04).¹⁹

If the CSED fields on your transcript are blank, that often signals an open suspension from an unreversed TC 480, TC 520, TC 500, or TC 971 AC 065.¹⁹

Doing the Math

Start with the TC 150 date, or whatever assessment you’re tracking. Add ten years. Then work through every tolling event on the transcript and add the length of each suspension. When suspensions overlapped in time, count the overlapping period once, not twice. The result is your adjusted CSED. On complex accounts, this calculation is genuinely difficult, and the IRS itself sometimes gets it wrong. Pulling your own transcript and verifying the dates is often worth the effort, particularly if a levy or lien is pending on a debt that looks close to expiring.

1
Office of the Law Revision Counsel. 26 U.S.C. 6502 – Collection After Assessment
2
Internal Revenue Service. Internal Revenue Manual 35.9.2 – Procedures for Assessment of Tax
3
Taxpayer Advocate Service. Collection Statute Expiration Date (CSED)
4
Office of the Law Revision Counsel. 26 U.S.C. 6325 – Release of Lien or Discharge of Property
5
Office of the Law Revision Counsel. 26 U.S.C. 6331 – Levy and Distraint
6
eCFR. 26 CFR 301.6159-1 – Agreements for Payment of Tax Liabilities in Installments
7
Office of the Law Revision Counsel. 26 U.S.C. 6330 – Notice and Opportunity for Hearing Before Levy
8
Office of the Law Revision Counsel. 26 U.S.C. 6015 – Relief From Joint and Several Liability on Joint Return
9
Office of the Law Revision Counsel. 11 U.S.C. 362 – Automatic Stay
10
Office of the Law Revision Counsel. 26 U.S.C. 6503 – Suspension of Running of Period of Limitation
11
Internal Revenue Service. Time IRS Can Collect Tax
12
Internal Revenue Service. Extension of Deadlines – Combat Zone Service
13
Internal Revenue Service. IRM 5.14.2 – Partial Payment Installment Agreements and the Collection Statute Expiration Date
14
Office of the Law Revision Counsel. 28 U.S.C. 3201 – Judgment Liens
15
Internal Revenue Service. IRM 5.1.19 – Collection Statute Expiration
16
Internal Revenue Service. Get Your Tax Records and Transcripts
17
Internal Revenue Service. About Form 4506-T, Request for Transcript of Tax Return
18
Taxpayer Advocate Service. NTA Blog – Decoding IRS Transcripts and the New Transcript Format Part II
19
Internal Revenue Service. IRM 5.19.10 – Collection Operations Transcript Processing