Can I appeal a CO-201 or PR-201 denial?

Yes. Appealing is free and it is your legal right. For this code the odds are low: many denials are reversed when challenged with the right evidence. Fewer than 1 in 100 denials are ever appealed — insurers count on silence.

Who has to pay after a code 201 denial?

Usually your cost to pay. 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.

Denial code 201 · CO-201 / PR-201 · translated

Denial code 201: what it means — and how to fight it

Denial code 201 (shown on your EOB as CO-201 or PR-201) means: “Patient is responsible for amount of this claim/service through 'set aside arrangement' or other agreement.” In plain English: They're pointing to an agreement (like a workers'-comp set-aside) that makes this your cost.

low appealability Usually your cost to pay

What they're really saying

“Patient is responsible for amount of this claim/service through 'set aside arrangement' or other agreement.”

They're pointing to an agreement (like a workers'-comp set-aside) that makes this your cost.

Your odds

Check the math first — this is usually cost-sharing, not a judgment.

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 201 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.
Check whether this service is actually within the set-aside agreement's scope. Verify the agreement actually covers this service; set-aside funds have specific rules about what they pay.
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 201 mean?: They're pointing to an agreement (like a workers'-comp set-aside) that makes this your cost.
Can I appeal a CO-201 or PR-201 denial?: Yes. Appealing is free and it is your legal right. For this code the odds are low: many denials are reversed when challenged with the right evidence. Fewer than 1 in 100 denials are ever appealed — insurers count on silence.
Who has to pay after a code 201 denial?: Usually your cost to pay. 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.