Time Limits for IRS Tax Assessments

After you file a tax return, the IRS has a limited amount of time to review the return and make changes. This deadline is called the assessment statute expiration date (ASED), and it also affects how long the IRS has to audit your tax return. 

If you're dealing back taxes or unfiled returns, you may want to know how the ASED works and how it affects your unique situation. 

To get help now, use TaxCure to find a licensed local tax pro. TaxCure features a directory of curated tax attorneys, CPAs, and enrolled agents from around the country, and you can filter the search results to ensure you find a pro with the experience and credentials you need. 

What Is the Assessment Statute Expiration Date (ASED)?

The Assessment Statute Expiration Date (ASED) is the last day the IRS can assess taxes on a filed tax return. In most cases, the IRS has three years from the later of the return due date or the date you filed. 

For example, say that you filed your 2024 tax return on March 1, 2025, and it was due on April 15, 2025. The assessment deadline is April 15, 2028. However, if you filed that return late on June 30, 2025, the ASED would be June 30, 2028.

If you report 25% or less of your income, the assessment statute extends from three years to six years. This extended timeline often comes into play when the IRS is auditing a current tax return and notices that you have significantly underreported your income. Then, the agency may decide to go back and look at the last six years of returns. 

However, in cases where the IRS believes that you filed a false or fraudulent return in an attempt to evade tax, there is no statute of limitations for assessment. If fraud is involved, the IRS can go back an unlimited amount of time to assess the tax. 

Note that the unlimited time limit only applies to civil tax fraud. If the IRS wants to bring criminal tax fraud charges against you, it only has three years in some cases and six years in others—the timing depends on the type of law alleged to have been broken.

If you don't file a return, the statute of limitations for assessment never starts. Legally, the IRS can go back an unlimited amount of time to assess tax in a tax period that you haven't filed. 

Why the ASED Matters for People with Tax Problems

Although the ASED may seem like an obscure law for most taxpayers, it has a direct impact on a number of different problems. 

• Unfiled returns - If you have unfiled returns, you should be aware that there is no time limit to prevent the IRS from looking back and assessing the tax against you. However, if you come forward voluntarily, you usually only have to file the last six years of tax returns to get back into compliance.
• Amended returns - You can amend returns indefinitely, and often, amending incorrect returns can help reduce how much you owe to the IRS. However, if you want to amend a return to claim a refund, you only have three years (or two years from the date of payment if later).
• Audits - If you're worried about a tax audit, the ASED can give you some reassurance on the time frame during which your returns may be subject to audit. 

When you work with an experienced tax pro, they will note the ASED in relation to your tax returns. As needed, they will ensure that you file returns with that date in mind, and they will leverage the deadline to your advantage whenever possible. 

Common Scenarios That Affect the Assessment Deadline

There are a few very relatively common situations that may affect the assessment deadline. Consider the following:

Amended Tax Returns

Amending a tax return does not usually change the ASED. However, if you file your amended return within 60 days of the original ASED or after the ASED, the IRS gets 60 days to review the return and assess additional tax as necessary.

Audits

An audit also does not extend the ASED. However, in most cases, the IRS will ask you to sign an agreement to extend the ASED during the audit process. You can say no to this request, but if you agree to extend the deadline, the extension can be to a specific date or for an open-ended time period that ends when the audit ends. 

If you don't agree to extend the deadline, the IRS will usually work quickly in the time they have available. They will usually try to assess a tax against you in that time and send you a Notice of Deficiency (explained below). Then, at that point, you can appeal with the Tax Court, or you can pay under protest and request a tax refund.

To get you to extend the deadline, the IRS may ask you to complete Form 872 (Consent to Extend the Time to Assess Tax). To be on the safe side, you should consult with a tax pro before making this decision.

Substitute for Return 

As noted above, there is no assessment deadline if you don't file a return. However, the IRS may file a Substitute for Return (SFR) for you to determine how much you owe. The clock on the assessment statute of limitations does not start running with an SFR. 

However, if you file a return after receiving an SFR, the clock starts running at that point. Many people decide to file after receiving an SFR because these IRS-generated returns often overstate your tax liability. If you don't respond to the SFR, the agency may issue a Notice of Deficiency, explained in the following section.

If you want to address your unfiled returns, check out this guide to filing back taxes.

Notice of Deficiency

The IRS may send you a Notice of Deficiency if they have adjusted your tax return or filed an SFR. You have 90 days to respond (150 if you are out of the country), and if you don't respond, the IRS will assess the taxes. 

The ASED gets suspended when the IRS sends this notice. The clock pauses the day the IRS sends the letter, and if you appeal, it stays paused until 60 days after the Tax Court makes a decision. 

To give you an example, imagine that you file a 2024 tax return early and the ASED is April 15, 2028 (three years after the filing deadline). The IRS reviews your return, assesses additional tax, and sends you a Notice of Deficiency on June 15, 2026. You decide to appeal and you receive a Tax Court decision six months later on December 15, 2027. Then, the IRS adds an additional 60 days. 

The six months from the date of the notice to the day of the Tax Court decision plus the additional 60 days get added to the time limit, extending the ASED to December 14, 2028.

ASED Vs. the Collection Statute Expiration Date

The Collection Statute Expiration Date defines how long the IRS has to collect unpaid taxes after assessment. The CSED is 10 years from the assessment date, but it can be tolled for multiple actions including applying for a payment plan and appealing a collection action.

Like the ASED, the CSED time clock doesn't start running until a return has been filed or the taxes have been assessed in another way.

FAQs About the Assessment Statute Expiration Date

What is the IRS Assessment Statute Expiration Date (ASED)?

The ASED is the date after which the IRS can no longer assess taxes on a filed tax return. The ASED is three years after the return was filed, and during this time frame, the IRS can review the return and assess tax. 

The ASED is six years after you file if you only reported 25% or less of your income. The ASED doesn't start if you don't file your returns. It also doesn't apply if you filed a fraudulent return, regardless of whether or not you reported more than 25% of your income.

What is the audit statute of limitations?

This is another way to refer to the ASED. The IRS only audits returns if the tax assessment time limit has not expired. If the IRS couldn't assess tax against you, there would be no point in auditing the return. 

Does the IRS have unlimited time to assess taxes on unfiled returns?

Yes, the IRS has an unlimited amount of time to assess taxes on unfiled returns. 

What happens if the IRS assesses taxes against you?

If the IRS assesses taxes against you, the agency will send you a notice. The notice varies depending on whether the agency adjusts a mistake in your tax return, audits you and assesses taxes, or issues a notice of Deficiency after an SFR. 

The assessment may include penalties such as the failure-to-file penalty if you didn't report the taxes on your return or the accuracy-related penalty if you significantly understated the tax due on your return. You have a chance to respond to the assessment if you disagree. If you agree, you may want to request penalty abatement and set up payments if you can't pay in full.

How can filing an old return help start the ASED clock?

If you file an old return, the clock starts on the ASED. Now, the IRS only has three years to review the return and assess taxes against you. Before you filed, the IRS could theoretically go back an unlimited amount of time.

What’s the difference between the ASED and the CSED?

The ASED determines how long the IRS has to assess taxes against you. The CSED determines how long the IRS has to collect taxes once they have been assessed.

Can an attorney help reduce my IRS debt using the ASED?

Not necessarily. However, an attorney can leverage this deadline to your advantage in cases where it applies. 

Get Help With Unpaid Taxes, Unfiled Returns, Audits, and More

Navigating the IRS's complex rules and deadlines can be confusing and frustrating, and when it comes to deadlines like the ASED or the refund expiration date, there isn't any leeway.

If you're having tax problems such as unfiled returns, unwanted assessments, audits, unpaid taxes, or other issues, you need a tax professional who focuses on resolving IRS tax problems. Tax relief is a very specific specialty, and to protect yourself, you should select a tax pro with experience. 

Using TaxCure, you can search for tax professionals in your area, and you can filter the results by their experience with certain problems and solutions. An experienced tax pro can help you negotiate with the IRS and manage assessment and collection deadlines. Don't delay. Get help now.