The CP21B is straightforward good news — the IRS processed a change to your return and the result is a refund coming your way.
This notice typically follows an amended return you filed, an IRS correction, or an adjustment from a prior audit or notice response where the outcome was in your favor. The CP21B confirms the change and tells you when to expect the refund.
What the CP21B means
CP21B means a specific change was made to your tax account — either by you through an amended return or by the IRS through a correction — and that change resulted in an overpayment. The IRS will issue a refund for the overpaid amount.
The notice shows the tax year affected, the nature of the change, and the refund amount. In most cases no action is required beyond reviewing the notice to confirm the figures match what you expected.
What to do
Compare the refund amount against what you expected from the change. If you filed an amended return, confirm the refund reflects the corrections you submitted. If the IRS made the change on its own, verify that the adjustment is accurate.
If the amount looks correct, wait for the refund — it typically arrives within 2 to 3 weeks of the notice date for direct deposit, or 4 to 6 weeks for a check.
If you believe the refund amount is wrong, respond in writing within 60 days with documentation explaining the discrepancy.
Frequently asked questions
How long until my CP21B refund arrives? The notice usually includes an estimated date. If it doesn’t arrive within that window, check your IRS online account for the current status.
What if I filed an amended return several months ago and just now received a CP21B? Amended returns take significantly longer to process than original returns — often 16 to 20 weeks or more during peak periods. A CP21B arriving months after filing is normal.