When a CP2000 notice goes unanswered – or when the IRS and a taxpayer cannot reach agreement through the CP2000 response process – the IRS issues a CP3219A. These two notices are related but legally distinct.

Understanding what changes when a CP2000 becomes a CP3219A determines what you can still do, how much time you have, and what the legal consequences are if no action is taken.

This article explains the key differences between the CP2000 and the CP3219A, how the timeline and your legal rights shift at each stage, and what the required actions are after receiving the CP3219A.

What a CP2000 Is: A Proposal

A CP2000 is a notice generated by the IRS Automated Underreporter (AUR) program. It is a proposed change to your tax return, not a final determination. The notice reflects a discrepancy between the income reported on your return and the income reported to the IRS by third-party payers (employers, financial institutions, clients, and others).

At the CP2000 stage, the IRS has not assessed any additional tax. It is asking you to confirm, correct, or dispute the proposed changes. You have a 60-day window to respond, and the matter can be fully resolved at this stage – either through agreement, through a documented dispute that the IRS accepts, or through a combination of both.

The CP2000 is also not a formal audit. It is an automated matching notice. Your rights at this stage are the right to respond and the right to be heard through the correspondence process.

What a CP3219A Is: A Legal Notice

The CP3219A is the Statutory Notice of Deficiency. Its legal basis is Internal Revenue Code Section 6212, which requires the IRS to issue this specific type of notice before it can assess additional income tax beyond what was voluntarily reported on a return. The CP3219A is not a proposal – it is the IRS’s formal and final determination, for purposes of the assessment process, that additional tax is owed.

The issuance of a CP3219A marks the point at which the matter formally transitions from an administrative review to a pre-litigation posture. At this stage, the taxpayer’s primary formal recourse is to petition the United States Tax Court. All other avenues for contesting the proposed tax – through IRS correspondence, through the AUR unit, through informal negotiation – are still technically available but are no longer the primary procedural pathway.

Key Differences Between CP2000 and CP3219A

Legal Status

A CP2000 is an administrative proposal with no binding legal effect until it is either agreed to or allowed to proceed to a Notice of Deficiency. A CP3219A is a legally operative document under the Internal Revenue Code. It triggers a jurisdictional window for Tax Court access and, if that window closes without a petition, it authorizes the IRS to assess the tax without further process.

Response Deadline

The CP2000 response deadline is 60 days from the notice date. Missing this deadline does not cause the tax to be immediately assessed – it causes the case to advance toward the CP3219A stage. The CP3219A carries a 90-day deadline (150 days for addresses outside the United States) for filing a Tax Court petition. This deadline is jurisdictional, meaning the Tax Court has no authority to hear the case if the petition is filed after the window closes. There is no extension mechanism.

What You Can Do Within Each Window

During the CP2000 window, your options are broad: agree with all or some of the proposed changes, dispute any or all items with documentation, request an extension, contact the payer to correct an erroneous information return, or engage a tax professional to handle the response. The matter can be resolved entirely through correspondence.

During the CP3219A window, your primary formal option is to petition the Tax Court. Informal resolution remains possible – the IRS will often negotiate settlements even after issuing a Notice of Deficiency, and many Tax Court cases are resolved before trial – but the formal procedural framework has shifted from correspondence to litigation.

Effect on Assessment

The IRS cannot assess the proposed tax while a valid CP2000 response is pending review. It also cannot assess the tax during the 90-day (or 150-day) period following the CP3219A. Once the Tax Court petition period expires without a petition, the tax is assessed as a matter of course. This assessment is not appealable through the Tax Court after the window has closed.

Penalty and Interest Treatment

Both the CP2000 and CP3219A carry the same proposed accuracy-related penalty (typically 20% of the additional tax), and interest accrues from the original return due date in both cases. The difference is timing: at the CP2000 stage, there is still a meaningful window to contest the penalty through abatement requests submitted with the response. At the CP3219A stage, penalty abatement through informal channels becomes less straightforward, and the Tax Court can address both the underlying tax and associated penalties.

Why a CP3219A Is Issued

A CP3219A is issued in one of three circumstances:

• The taxpayer did not respond to the CP2000 within the 60-day window (or an extension period, if one was granted)
• The taxpayer responded to the CP2000 but disagreed with the proposed changes, and the IRS reviewed the response and maintained its position
• The taxpayer and the IRS reached partial agreement but the IRS is maintaining the proposed changes on the unresolved items

In the first case, the CP3219A is the automatic next step. In the second and third cases, the CP3219A follows the IRS’s determination after reviewing the taxpayer’s response. The IRS will typically send a preliminary letter explaining its decision before issuing the CP3219A in cases that went through the dispute process.

What You Must Do After Receiving a CP3219A

Note the Notice Date Immediately

The 90-day window begins on the date printed on the CP3219A, not the date you received it. If mail delivery was delayed, you may have fewer than 90 days from actual receipt. Check the notice date and calculate the petition deadline immediately. Missing this deadline eliminates your Tax Court option.

Decide Whether to Petition the Tax Court

Tax Court jurisdiction is the primary protection the CP3219A window provides. Filing a petition preserves your right to have the proposed assessment reviewed by an independent judicial body before it becomes a legally enforceable debt. You do not need to be confident of winning to petition – the filing itself keeps your options open and creates space for negotiation and settlement.

The Tax Court’s Small Tax Case (S-case) procedure is available for disputes involving $50,000 or less in tax per year. S-cases use simplified procedures, and taxpayers can represent themselves. For amounts above that threshold, professional representation is strongly advisable.

Explore Settlement Before Trial

Filing a Tax Court petition does not mean the case will go to trial. The IRS Office of Chief Counsel handles Tax Court cases on behalf of the government, and IRS attorneys frequently negotiate settlements that are more favorable than the original proposed assessment – particularly when the taxpayer has documentation that was not fully considered during the CP2000 phase. Many CP3219A matters filed in Tax Court are resolved through stipulated agreements before a judge ever hears the case.

Do Not Ignore the CP3219A

Ignoring the CP3219A has the same effect as letting the 90-day window expire: the IRS assesses the full proposed tax. Unlike the CP2000, where ignoring the notice led to the CP3219A and still left options open, ignoring the CP3219A leads directly to formal assessment with no further pre-assessment procedural steps available.

After the 90-Day Window: What Changes

Once the 90-day period expires without a Tax Court petition, the IRS proceeds to formal assessment. At that point:

• The tax becomes an assessed liability on your IRS account
• A formal bill (typically CP14) is issued
• Interest continues to accrue and the failure-to-pay penalty begins
• The IRS collection sequence initiates: CP501, CP502, CP503, CP504
• Federal tax lien filing becomes possible
• Levy action can follow after the Final Notice of Intent to Levy is issued

Post-assessment options include audit reconsideration (submitting evidence to the IRS that the assessment was incorrect), amended return filing for the year in question, installment agreement or offer in compromise for payment, and Collection Due Process hearing rights once a levy notice is issued.

The Form 5564 Waiver

The CP3219A includes Form 5564, the Notice of Deficiency Waiver. If you sign and return this form, you waive your right to petition the Tax Court and consent to the immediate assessment of the proposed tax. Signing Form 5564 makes sense only if you have reviewed the proposed changes and are satisfied that they are accurate. It accelerates the process, which can be useful if you have decided to agree and want to arrange payment quickly. Do not sign Form 5564 if you have any intention of disputing any portion of the proposed changes.

Summary

A CP2000 is a proposal that can be resolved through correspondence. A CP3219A is a Statutory Notice of Deficiency that triggers a 90-day window for Tax Court access and, if unanswered, leads directly to formal tax assessment. The key practical change between the two is the formality of your remaining options and the rigidity of the deadline. For the full escalation picture before the CP3219A stage, see our article on what happens after a CP2000 if you don’t respond. For a complete breakdown of what the Notice of Deficiency authorizes and what your legal rights are, see our guide on understanding the notice of deficiency.