Quick Answer
Prior authorization is a binding coverage decision — if approved, the insurer is committed to paying (subject to eligibility at the time of service). Predetermination is a non-binding cost estimate; it tells you what the insurer would pay if the claim were submitted today, but it can be reversed at adjudication. Always request prior auth, not predetermination, for any service costing >$1,000. Confusing the two is one of the most common causes of "surprise" balance bills.
Last updated: 2026-05-26 · Source: AppealArmor · About the authors
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Definition: Required pre-approval from insurance before specific medications, treatments, or procedures will be covered. Doctor CANNOT provide treatment without it (or you pay full cost).
Definition: Voluntary estimate of coverage BEFORE treatment is provided. You (or your doctor/dentist) asks, "Will you cover this if we do it?" Insurance gives non-binding answer.
Action: MUST appeal if denied
Action: Can appeal OR proceed with treatment and appeal claim denial later
Use when: Treatment is planned but not yet done, you want coverage certainty before proceeding
Use when: Treatment is medically necessary NOW, you're confident in medical justification
Strategic Consideration: Predetermination denials are often based on incomplete information. You might have better success appealing the actual claim AFTER treatment, when you have complete medical records, outcome documentation, and findings discovered during treatment. Risk: You might be responsible for full cost if claim is also denied.
| Feature | Prior Authorization | Predetermination |
|---|---|---|
| Purpose | Required pre-approval for coverage | Voluntary coverage estimate |
| Binding? | Yes - approval required for coverage | No - estimate only |
| Required? | Yes - by insurance plan | No - patient/provider requests |
| Timeline | 72 hours (urgent) or 30 days (standard) | Varies, typically 15-30 days |
| Appeal Rights | Formal process, external review, state complaints | Less formal, varies by insurer |
| If Denied | MUST appeal before treatment or pay full cost | Can appeal OR proceed and appeal claim later |
| Common For | Expensive drugs, imaging, specialty treatments | Dental work, elective procedures, high-cost planning |
Mistake: Patient gets predetermination approval for $2,000 dental crown, thinks coverage is guaranteed, proceeds with treatment.
Reality: When actual claim is submitted, insurance denies due to "not medically necessary" (cosmetic). Patient owes full $2,000.
Solution: Understand predeterminations are estimates only. Request prior authorization (if available) for binding decision.
Mistake: Patient receives prior authorization denial but thinks it's just a coverage estimate they can ignore.
Reality: Prior authorization denials are binding. Without approval, treatment won't be covered. Must appeal.
Solution: If letter says "prior authorization required" or "coverage denied", you MUST appeal for coverage.
Mistake: Doctor says "just get the treatment, we'll appeal the claim after."
Reality: If prior authorization was REQUIRED and denied, claim will be automatically rejected for "no prior auth." Appeal must happen BEFORE treatment.
Solution: Always appeal prior authorization denials before receiving treatment.
Upload your denial letter or coverage determination. AppealArmor drafts an appeal from the denial letter you have; check whether it is a prior authorization or a predetermination first.
Analyze My Denial — FreeFree, always. No account. You review every word before you send it — and we never send anything to your insurer. You do.
Complete step-by-step guide to appealing a prior authorization denial with timelines and strategies.
Free prior authorization appeal letter template with clinical evidence sections that overturn PA denials.
Understand the difference between 'not medically necessary' and 'experimental' denials and how to fight each.
How to qualify for 72-hour expedited prior authorization review when treatment delay poses serious risk.
Upload your denial letter — a PDF or a photo of the paper letter works. You check every detail we read from it, then we draft the appeal and quote the federal appeal rules for your type of plan. You read it, change anything you want, and send it yourself.
Start my free appeal →Free, always. No account. You review every word before you send it — and we never send anything to your insurer. You do.
