medium urgencytypical response window: 20 days
IRS Notice Letter 12C: Missing Information Request
What it means
Your return is held pending missing forms/schedules (often Form 8962 or 1095-A).
What to do
Send exactly what's requested to the address on the letter.
Verify it's real. The IRS contacts you by mail first — never by phone, email, or text demanding payment. The notice includes a number in the top-right corner and instructions on irs.gov. When in doubt, log into your IRS online account rather than calling a number on the letter.
FAQ
What is IRS notice Letter 12C?
Your return is held pending missing forms/schedules (often Form 8962 or 1095-A).
How long do I have to respond to Letter 12C?
You typically have 20 days from the notice date. The deadline is printed on the notice itself — use that, not this estimate.
Should I get professional help for Letter 12C?
Usually not required — but if the amounts are wrong or you also owe other years, a professional review is cheap insurance.