Who has to pay after a code 284 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 284

Denial code 284: what it means — and how to fight it

Denial code 284 (shown on your EOB as CO-284 or PR-284) means: “Precertification/authorization/notification/pre-treatment number may be valid but does not apply to the billed services.” In plain English: An authorization existed, but not for this service, provider, or place of care. The approval and the bill do not match.

high appealability Who owes depends on the details

What they're really saying

“Precertification/authorization/notification/pre-treatment number may be valid but does not apply to the billed services.”

An authorization existed, but not for this service, provider, or place of care. The approval and the bill do not match.

Your odds

Strong — this type of denial has real weaknesses.

Frequently overturned — the care was approved, just recorded against the wrong thing.

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 284 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.
Compare your authorization letter to the bill line by line and find the mismatch. Get a copy of the authorization and compare it line by line to the claim: procedure codes, provider name and tax ID, facility, dates, and number of visits. Most of these are clerical mismatches the provider can correct and rebill. If the plan authorized one thing and your doctor did something clinically necessary instead, request a retroactive authorization with a note explaining what changed during care.
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 284 mean?: An authorization existed, but not for this service, provider, or place of care. The approval and the bill do not match.
Can I appeal a CO-284 or PR-284 denial?: Yes. Appealing is free and it is your legal right. For this code the odds are high: Frequently overturned — the care was approved, just recorded against the wrong thing. Fewer than 1 in 100 denials are ever appealed — insurers count on silence.
Who has to pay after a code 284 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.