UnitedHealthcare · Rezdiffra Nash · US health-plan appeal rights

Rezdiffra Nash denied as experimental or investigational by UnitedHealthcare?

Q: How long do I have to appeal a UnitedHealthcare Rezdiffra Nash denial?

Internal appeal window: Typically 180 days from the denial date. External review window: Typically 60–120 days after the final internal denial. The clock starts from the date on the denial letter.

An experimental denial requires the appeal to cite the FDA approval (if any), peer-reviewed phase III data, and the recognised specialty-society guideline that supports the treatment for your indication.

By Michael John Ryan, Founder & Privacy Officer, DenialHelp, LLC

Last reviewed 2026-05-10

Policy data current as of 2026-04-26

US health-plan appeal rights

Cite: Most US health plans have appeal rights under either the ACA, ERISA, or Medicare/Medicaid rules

Most US health plans are required by federal law to give you both an internal appeal (where the insurer reconsiders) and an external review (where an independent reviewer decides). The exact timelines and processes depend on what kind of plan you have — marketplace / employer group, self-funded, Medicare Advantage, or Medicaid MCO — but in every case there's a window after the denial during which you have the right to fight it.

Internal appeal window

Typically 180 days from the denial date

External review window

Typically 60–120 days after the final internal denial

What UnitedHealthcare typically requires

UnitedHealthcare's specific coverage criteria for rezdiffra nash are defined in its own published medical/coverage policy and the FDA-approved prescribing label. A successful appeal documents that your medical records satisfy each criterion those sources list — confirmed diagnosis, any required prior treatments (with dates and outcomes), and clinical severity. If the exact criteria weren't included with your denial, request them in writing; your appeal then maps each requirement to the matching fact in your chart.

Source policy: OptumRx Prior Authorization — Rezdiffra (Resmetirom) for NASH/MASH

The UnitedHealthcare angle on Rezdiffra Nash

## Why UHC Denies Rezdiffra for NASH as Experimental — and Why You Can Appeal

Rezdiffra (resmetirom) received full FDA approval for metabolic dysfunction-associated steatohepatitis (MASH) with moderate-to-advanced liver fibrosis. Despite this, UnitedHealthcare may initially issue an experimental or investigational denial — sometimes because the coverage policy for a newly approved drug has not yet been updated, or because UHC is applying an outdated policy that predates FDA approval.

A full FDA approval for the specific indication at issue is the strongest possible counter to an experimental denial. Under UHC's own coverage determination framework, and under most state insurance laws, a drug cannot be deemed experimental once the FDA has granted full marketing approval for the condition being treated. This type of denial has a high overturn rate on appeal.

## Federal Appeal Framework

Internal appeal: File within 180 days of the denial. For a pre-service denial, UHC must respond within 30 days; post-service, within 60 days.
Expedited review: If the patient's condition is rapidly progressing (e.g., advancing fibrosis, portal hypertension complications), request expedited review for a 72-hour turnaround.
External review (ACA §2719): After a final adverse internal determination, you have approximately four months to request independent external review. IRO decisions are binding on UHC.
ERISA §503: For self-funded employer plans, request the full administrative record and invoke full-and-fair review rights.

## Documentation to Gather

FDA approval documentation: Print the current FDA drug label from DailyMed (dailymed.nlm.nih.gov) showing the approved indication and the date of approval. Confirm the patient's diagnosis matches the approved indication exactly.
Diagnosis and staging confirmation: Liver biopsy pathology report or validated non-invasive fibrosis assessment confirming MASH with the fibrosis stage within Rezdiffra's approved indication.
Prescriber medical-necessity letter: A letter from the hepatologist or gastroenterologist citing the FDA approval, explaining why Rezdiffra is medically necessary for this specific patient, and stating that the treatment is consistent with current AASLD (American Association for the Study of Liver Diseases) guidelines.
UHC policy challenge: Identify the date UHC's cited coverage policy was last updated. If it predates FDA approval of Rezdiffra for MASH, explicitly note this discrepancy in the appeal letter.

## Criteria-Mapping Structure

Obtain UHC's coverage policy for Rezdiffra or its experimental/investigational determinations policy. Copy each criterion used to classify a drug as experimental. For each criterion, document how Rezdiffra fails to meet it — specifically: (1) FDA has granted full approval (not accelerated or conditional), (2) the approval covers the exact indication for which the drug is being prescribed, and (3) the prescribing is consistent with the approved labeling. Attach the FDA approval letter or label as an exhibit.

Next steps

Find the date on the denial letter — your appeal window starts there.
Read your plan's Summary of Benefits and Coverage (SBC) for the specific deadlines.
Request the insurer's claim file in writing — they must provide it.
Submit your appeal in writing with new clinical evidence and a physician statement.

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Related appeal guides

Other UnitedHealthcare appeals

Other denial reasons for UnitedHealthcare Rezdiffra Nash

denied as not medically necessary denied for failing step therapy denied as non-formulary denied for missing prior authorization denied as not FDA-approved for this use

This guide describes general US federal appeal rights based on Most US health plans have appeal rights under either the ACA, ERISA, or Medicare/Medicaid rules. Your specific plan documents (Summary of Benefits and Coverage, Evidence of Coverage) override anything here. DenialHelp is not your lawyer and not your physician — we draft appeal letters that your physician signs. Outcomes depend on your insurer's decision and factors outside our control. Reviewed by Michael John Ryan on 2026-05-10. Editorial standards: denialhelp.com/authors.