Who has to pay after a code 224 denial?

Who owes depends on the details. The letters in front of the number matter: CO (contractual obligation) usually means an in-network provider must absorb it, while PR (patient responsibility) means the plan says you owe it.

How long do I have to appeal?

It depends on your coverage: 180 days for most employer and marketplace plans, 120 days for Original Medicare, about 90 days for Medicaid (varies by state), and only 65 days for Medicare Advantage. Set your deadline clock before you do anything else.

All denial codes · code 224

Denial code 224: what it means — and how to fight it

Denial code 224 (shown on your EOB as CO-224 or PR-224) means: “Patient identification compromised by identity theft. Identity verification required for processing this and future claims.” In plain English: The plan flagged your account for possible medical identity theft. Claims are frozen until you prove who you are.

high appealability Who owes depends on the details

What they're really saying

“Patient identification compromised by identity theft. Identity verification required for processing this and future claims.”

The plan flagged your account for possible medical identity theft. Claims are frozen until you prove who you are.

Your odds

Strong — this type of denial has real weaknesses.

Legitimate claims are generally paid once identity is verified — but act fast, this blocks future care too.

Fewer than 1 in 100 denied claims are ever appealed. When people do appeal, roughly 4 in 10 win the first round — and independent external review overturns 40–50% of what reaches it.

How to appeal a code 224 denial

Decode. You just did — this page is step one.
Set your clock. 180 days for most employer and marketplace plans, 120 for Original Medicare, ~90 for Medicaid, only 65 for Medicare Advantage.
Urgent? If this is care you still need, call and request an expedited appeal — they must decide within 72 hours.
Call the number on your card and ask for the fraud unit to start identity verification. Call the plan's fraud or special investigations unit immediately and ask exactly what verification they need. Request a copy of your claims history to see what was billed that was not yours, and dispute those in writing. Consider a report to the FTC at identitytheft.gov and a credit freeze, since medical identity theft rarely stays medical.
Send it certified. Letter plus evidence, keep copies of everything.
Escalate. Denied again? Independent external review — a doctor who doesn't work for your insurer decides.

Do it in minutes, free

The AppealClock tool translates your denial, drafts your appeal letter, computes your exact deadline — and watches the clock so you don't have to. No account. Your medical details never leave your device.

Start your appeal & set your clock →

Common questions

What does denial code 224 mean?: The plan flagged your account for possible medical identity theft. Claims are frozen until you prove who you are.
Can I appeal a CO-224 or PR-224 denial?: Yes. Appealing is free and it is your legal right. For this code the odds are high: Legitimate claims are generally paid once identity is verified — but act fast, this blocks future care too. Fewer than 1 in 100 denials are ever appealed — insurers count on silence.
Who has to pay after a code 224 denial?: Who owes depends on the details. The letters in front of the number matter: CO (contractual obligation) usually means an in-network provider must absorb it, while PR (patient responsibility) means the plan says you owe it.
How long do I have to appeal?: It depends on your coverage: 180 days for most employer and marketplace plans, 120 days for Original Medicare, about 90 days for Medicaid (varies by state), and only 65 days for Medicare Advantage. Set your deadline clock before you do anything else.