Can I appeal a CO-171 or PR-171 denial?

Yes. Appealing is free and it is your legal right. For this code the odds are medium: Corrected place-of-service coding fixes many of these. Fewer than 1 in 100 denials are ever appealed — insurers count on silence.

Who has to pay after a code 171 denial?

Usually the provider's problem — not yours. 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 171

Denial code 171: what it means — and how to fight it

Denial code 171 (shown on your EOB as CO-171 or PR-171) means: “Payment is denied when performed/billed by this type of provider in this type of facility.” In plain English: They won't pay this provider for this service in this setting. Often a coding or place-of-service issue the provider can correct.

medium appealability Usually the provider's problem — not yours

What they're really saying

“Payment is denied when performed/billed by this type of provider in this type of facility.”

They won't pay this provider for this service in this setting. Often a coding or place-of-service issue the provider can correct.

Your odds

Worth fighting — many of these get fixed.

Corrected place-of-service coding fixes many of these.

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 171 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.
Ask the provider to check the place-of-service code. Ask the provider to verify the place-of-service and provider-type coding and resubmit if wrong. If the setting was medically required, add documentation supporting it.
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 171 mean?: They won't pay this provider for this service in this setting. Often a coding or place-of-service issue the provider can correct.
Can I appeal a CO-171 or PR-171 denial?: Yes. Appealing is free and it is your legal right. For this code the odds are medium: Corrected place-of-service coding fixes many of these. Fewer than 1 in 100 denials are ever appealed — insurers count on silence.
Who has to pay after a code 171 denial?: Usually the provider's problem — not yours. 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.