Service denied because prior authorization wasn't obtained

What this looks like in practice

Most commercial insurance contracts state that the provider — not the patient — is responsible for obtaining prior authorization for in-network services. When the provider fails to and the claim is denied, federal contract law and most state laws say the provider must absorb the cost. Several states (California, Texas, Washington, others) have explicit "hold harmless" rules for in-network patients in this situation.

The practical pattern: patient gets a denial letter saying "prior authorization was not obtained." Hospital sends a bill anyway. Patient calls insurance, who confirms the provider was responsible. The dispute goes back to the hospital's billing department to take the loss internally rather than passing it to the patient.

How to spot it on a bill

• 01.Insurance EOB shows denial reason: 'No prior authorization,' 'Prior auth required,' or similar.
• 02.The service was rendered at an in-network facility.
• 03.You weren't told in advance that prior auth was needed and didn't sign a separate waiver assuming financial responsibility.

What to write — ready-to-paste language

Replace the bracketed fields with your specific details. Send by certified mail with return receipt, or via the hospital’s patient portal if it offers documented messaging. Keep a copy.

I'm writing about the bill dated [date] for service on [date of service]. My insurance EOB shows the claim was denied for failure to obtain prior authorization. As an in-network patient at [facility], the provider's contract with my insurance plan ([insurer name]) makes the provider responsible for obtaining prior authorization. I did not sign a waiver of financial responsibility for this service. Per the in-network contract terms, I am not financially responsible for charges that should have been pre-authorized by the provider. Please write off this balance or escalate to the provider relations team at [insurer]. If state law in [state] applies a hold-harmless rule for prior-auth denials, please apply it.

This is a starting point, not legal advice. Your specific situation may warrant additional details. Our scan tool drafts this letter automatically with your bill’s specifics filled in.

Related scenarios

• Insurance denied for 'not medically necessary' — your appeal rights

  ERISA and ACA give every insured patient the right to appeal denied claims. Internal and external review processes are mandatory; insurers must follow specific timelines.

• Step therapy denied — must try cheaper drug first

  'Step therapy' or 'fail first' rules require trying a lower-cost drug before insurance covers a more expensive one. Federal and most state laws give patients a way to bypass when medically necessary.

• Medicare Advantage denied a service Original Medicare would cover

  Medicare Advantage plans (Part C) must cover everything Original Medicare covers — and OIG has flagged repeated patterns of inappropriate denials. The MA appeal process exists for exactly this.

Common questions