Reviewed September 2026.
Cross-line denials (auto, renters, health) start in Denied insurance claims. This page is the health-claim appeal path: EOBs, clinical criteria, internal appeals, and external review.
Name the denial reason first
| Denial on the EOB / letter | First move |
|---|---|
| Not medically necessary / experimental | Medical necessity appeal with clinician letter and notes |
| Prior authorization missing or mismatched | Fix or appeal the auth (Prior authorization) Full pre-service path: Appeal a denied prior authorization. |
| Out of network / not a covered benefit | Check SPD/EOC against the denial; request review when you dispute the determination (network and benefit denials can be appealed) |
| Coding error | Provider corrects CPT/modifiers and rebills; you track the claim number and keep the appeal deadline |
| Eligibility / not a member on DOS | Verify enrollment and effective dates with HR/insurer before assuming a coding fix |
| Duplicate claim | Reconcile original claim numbers; ask which claim remains open |
| Timely filing | Get submission proof or plan exceptions; a corrected-code rebill is not always the remedy |
| Drug not on formulary | Formulary exception request with prescriber support |
Match CPT/HCPCS and diagnosis codes on the claim to what your clinician ordered (Medical bills and insurance).
Appeal sequence (post-service)
- Calendar the deadline printed on the denial (federal rules generally allow at least 180 days to file a post-service internal appeal). Urgent care decisions run on faster clocks; that speed is about the plan’s reply, not a reason to miss filing.
- Request the claim file / criteria used to deny (plan clinical policy or guideline ID).
- File the internal appeal via the portal or address on the letter. Attach chart notes, imaging, labs, and a plain cover letter with claim number and date of service.
- Ask the clinician’s office to submit a peer-to-peer or letter of medical necessity when the issue is clinical.
- If upheld, check external review rights (ACA Marketplace and many employer plans). File within the external-review window on the uphold letter.
- Tell the provider’s billing office you are appealing so they pause aggressive collections when possible.
Worked sketch: denied outpatient procedure
Jordan receives an EOB: claim $14,200 allowed, patient responsibility $14,200, reason “not medically necessary.” Deductible was already met. Appeal deadline: 180 days from the notice date.
| Day | Action |
|---|---|
| 1–3 | Download EOB + denial letter; request clinical criteria ID from the plan |
| 1–10 | Surgeon sends letter of medical necessity + last 6 months of notes |
| 14 | Jordan files internal appeal with claim #, CPT, and attachments |
| Decision | Plan overturns; reprocessed EOB shows plan pay + Jordan’s coinsurance only |
Jordan does not pay the full $14,200 on a medical card while the appeal is open unless the provider demands a deposit; Jordan gets any deposit policy in writing.
Checklist
- Separate clinical denials from coding/network denials before you write.
- File on time; keep portal screenshots and certified-mail receipts.
- Put the claim number in every subject line and letter.
- Escalate to external review when internal appeal upholds a clinical denial.
- Track provider billing so an appeal does not quietly become collections.
Educational only. Not legal or insurance advice. Appeal rights depend on plan type (self-funded ERISA, fully insured, Marketplace); read your denial letter and plan documents.