UnitedHealthcare · Rezdiffra Nash · US health-plan appeal rights

Rezdiffra Nash denied as duplicate or overlapping therapy 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.

If two medications appear duplicative on paper but serve different clinical purposes (e.g., short-acting vs long-acting), the appeal needs to spell out the clinical rationale for both.

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 Duplicate Therapy — and Why You Can Appeal

Rezdiffra (resmetirom) is the first FDA-approved medication specifically indicated for metabolic dysfunction-associated steatohepatitis (MASH, formerly called NASH) with moderate-to-advanced liver fibrosis. UnitedHealthcare sometimes issues a duplicate-therapy denial when a patient is already taking another agent — most commonly a GLP-1 receptor agonist, a vitamin E-based regimen, or another metabolic medication — on the theory that a second drug addressing overlapping metabolic pathways constitutes duplication.

This rationale is clinically contestable. Rezdiffra works through thyroid hormone receptor beta (THR-β) agonism, a distinct mechanism of action from GLP-1 agents, insulin sensitizers, or antioxidants. The prescribing label does not list these agents as contraindicated combinations, and leading hepatology societies do not treat them as interchangeable. A well-supported appeal explains the mechanistic distinction and the prescriber's rationale for combination use.

## Federal Appeal Framework

Internal appeal: File within 180 days of the denial. UHC must decide within 30 days (pre-service) or 60 days (post-service).
Expedited option: If the patient's liver disease is rapidly progressing, request expedited review; UHC must respond within 72 hours.
External review (ACA §2719): After exhausting internal appeals, approximately four months remain to request independent external review. An IRO reversal is binding.
ERISA §503: For employer-sponsored self-funded plans, invoke full-and-fair review rights and request the complete administrative file.

## Documentation to Gather

Diagnosis confirmation: Liver biopsy pathology report or validated non-invasive fibrosis staging (FIB-4, elastography) confirming MASH with the fibrosis stage specified in Rezdiffra's approved indication.
Mechanistic distinction letter: A letter from the prescribing hepatologist or gastroenterologist explaining that Rezdiffra's THR-β mechanism is not replicated by the concurrent agent(s), and that combination use is intentional and clinically justified.
Treatment response history: Documentation of the response (or lack thereof) to the existing therapy, with objective measures (liver enzymes, imaging, fibrosis scores), demonstrating that the concurrent agent alone has not achieved target disease control.
FDA label and guideline support: A copy of Rezdiffra's FDA-approved prescribing information and any applicable American Association for the Study of Liver Diseases (AASLD) guidance supporting use in this patient's fibrosis stage.

## Criteria-Mapping Structure

Obtain UHC's published coverage policy for Rezdiffra. Copy each criterion. For the duplicate-therapy criterion specifically, provide: (1) the name and mechanism of the concurrent agent, (2) the prescriber's explanation of why the mechanisms are distinct, (3) the clinical evidence that the concurrent agent is not addressing the MASH/fibrosis endpoint Rezdiffra targets, and (4) the chart documentation of ongoing fibrosis severity. Pair this with a clear statement that Rezdiffra is the only FDA-approved agent with this specific mechanism and indication.

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.

Get the letter drafted

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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 experimental or investigational

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.