Medicare Coverage for NASH, MASH, and Metabolic Fatty Liver Disease

For decades, fatty liver disease had no FDA-approved treatment. In March 2024 that changed: the FDA approved resmetirom (Rezdiffra), the first drug proven to reduce liver scarring in patients with metabolic-associated steatohepatitis — the disease most people still call NASH or, under the newer name, MASH. The drug costs roughly $47,000 per year at list price, but the Inflation Reduction Act’s $2,100 annual out-of-pocket cap on Part D made it genuinely reachable for Medicare beneficiaries for the first time. This guide explains how Medicare covers the full arc of MASH — from diagnosis through treatment, from comorbidity management through liver transplant — and what you can expect to pay.

Understanding the Name Change: NAFLD, NASH, MASLD, and MASH

If your doctor uses different terms than what you’ve heard before, you’re not confused — the medical community officially renamed the disease in 2023.

The rename reflects the root cause: it is not about alcohol avoidance — it is about metabolic dysfunction (obesity, insulin resistance, Type 2 diabetes, high triglycerides, high blood pressure). MASLD is now the umbrella term; MASH is the progressive, inflammatory form that leads to fibrosis, cirrhosis, and liver cancer. In everyday conversation and in most Medicare coverage documents, the older NASH terminology is still widely used. This guide uses MASH and NASH interchangeably to reflect both.

Why MASH Is a Medicare-Age Disease

MASH does not develop overnight. The typical patient has had metabolic syndrome for years before symptoms appear, which means the disease burden falls heavily on people in their 60s and 70s — the core Medicare population.

• An estimated 100 million Americans have some degree of MASLD
• Roughly 20–25 percent of people with MASLD will develop the inflammatory MASH form
• 70–75 percent of people with Type 2 diabetes have MASLD — the metabolic overlap is nearly universal
• MASH has now surpassed hepatitis C as the leading cause of liver-related deaths and liver transplants in the United States

The connection to Type 2 diabetes matters doubly for Medicare beneficiaries: not only does diabetes cause MASH, but MASH makes diabetes harder to control. Insulin resistance worsens with each stage of liver fibrosis. For a deeper look at how Medicare manages diabetes alongside liver disease, see the Medicare and diabetes coverage guide.

Part B: Diagnosing MASH

Diagnosing MASH requires distinguishing it from other liver diseases and staging the degree of fibrosis. Medicare Part B covers all of the diagnostic workup at 80 percent after the $283 Part B deductible (2026), leaving you 20 percent coinsurance.

Bloodwork and Liver Function Tests

Standard liver panels — ALT, AST, alkaline phosphatase, GGT, bilirubin — are covered as clinical lab tests. Elevated transaminases (ALT/AST) are often the first clue that something is wrong with the liver. Part B also covers the metabolic workup: fasting glucose, HbA1c, lipid panels, and the HOMA-IR calculation used to quantify insulin resistance.

Blood-based fibrosis scores — the FIB-4 index (calculated from age, platelet count, and ALT/AST) and the Enhanced Liver Fibrosis (ELF) test — are increasingly ordered as noninvasive first-line tools before imaging.

FibroScan (Transient Elastography)

FibroScan measures liver stiffness with ultrasound-based vibrations, giving a fibrosis score without a needle. Medicare Part B covers FibroScan under CPT 91200 as a diagnostic imaging procedure. The controlled attenuation parameter (CAP) score, measured simultaneously, quantifies the degree of fat infiltration. FibroScan has become the standard noninvasive first step in staging known or suspected MASLD.

Liver Biopsy

A liver biopsy remains the gold standard for definitively diagnosing MASH and staging fibrosis (F0–F4 on the Metavir or NASH CRN scale). It is required before prescribing Rezdiffra (the drug label specifies “moderate to advanced fibrosis, stages F2 and F3”). Medicare Part B covers percutaneous liver biopsy in an outpatient setting; if performed during an inpatient stay, it falls under Part A.

Abdominal Ultrasound and Advanced Imaging

Standard abdominal ultrasound (Part B, 20 percent coinsurance) detects moderate-to-severe fat infiltration and can screen for cirrhotic changes and nodules. For surveillance of hepatocellular carcinoma (see below), ultrasound is the first-line tool every six months. CT and MRI-based elastography are used when FibroScan results are inconclusive or when portal hypertension needs assessment — all covered under Part B.

The Rezdiffra Breakthrough: Part D Coverage for MASH

What Rezdiffra Is

Resmetirom (brand name Rezdiffra, made by Madrigal Pharmaceuticals) is a thyroid hormone receptor beta (THR-β) agonist. It works in the liver by activating the thyroid hormone pathway, which reduces fat synthesis, increases fat oxidation, and reduces liver inflammation. In the pivotal MAESTRO-NASH trial, 26 percent of patients on the 80 mg dose and 30 percent on the 100 mg dose achieved MASH resolution (vs. 10 percent on placebo), and meaningful fibrosis improvement was seen in 24–26 percent.

The FDA approved Rezdiffra on March 14, 2024, for adults with MASH and moderate to advanced fibrosis (stages F2–F3). It is not yet approved for F4 (cirrhosis), though trials in compensated cirrhosis are ongoing.

How Part D Covers It

Rezdiffra is placed on the specialty tier of most Part D formularies — the tier reserved for high-cost biologics and specialty medications. The list price is approximately $3,950 per month ($47,400 per year).

Before the Inflation Reduction Act, the math was devastating: a 25 percent specialty coinsurance up to the catastrophic phase meant thousands of dollars in monthly out-of-pocket costs. The IRA changed the structure fundamentally. Starting in 2025:

• Annual out-of-pocket cap: $2,100 — once you hit this ceiling, Part D covers 100 percent of drug costs for the rest of the year
• Monthly smoothing: the $2,100 is amortized across the year so costs don’t spike in January
• The cap applies to the entire year’s Part D spending, not just one drug

In practice, a Medicare beneficiary taking Rezdiffra will spend approximately $175/month on average once the cap is distributed, far below what the list price would otherwise imply. For a fuller explanation of how Part D works, see the Medicare Part D guide.

Prior Authorization and Step Therapy

Virtually every Part D plan requires prior authorization (PA) for Rezdiffra. Expect your gastroenterologist or hepatologist to document:

• Confirmed MASH diagnosis (biopsy-proven or strong noninvasive evidence at F2–F3)
• Failure or contraindication to standard metabolic management (diet, exercise, weight loss, diabetes control)
• Absence of contraindications (known cardiac arrhythmias, thyroid nodules with some plans)

Some plans also require a trial of pioglitazone (a generic thiazolidinedione that has AASLD guideline support for MASH in T2D patients, $10–15/month) before approving Rezdiffra. If PA is denied, the appeals process — especially with supporting documentation from a specialist — reverses denials at a meaningful rate.

Generic Alternatives Under Part D

Until a generic resmetirom is available (unlikely before 2031 at the earliest, given patent protection), other medications with evidence in MASH include:

Semaglutide’s role in MASH deserves a note: the ESSENCE Phase 3 trial (2024) showed meaningful MASH resolution in patients without diabetes using Wegovy-level doses. However, Medicare currently does not cover semaglutide/Wegovy for weight loss alone — only the Ozempic formulation for Type 2 diabetes. CMS is reviewing the landscape following the ESSENCE data. For a detailed breakdown of the GLP-1 coverage rules, see the Medicare GLP-1 and weight loss coverage guide.

Managing Comorbidities: The Metabolic Cluster

MASH almost never exists in isolation. The conditions that cause it — obesity, Type 2 diabetes, dyslipidemia, hypertension — are also the conditions most likely to kill the patient before cirrhosis does. Medicare covers all of these under Part B (office visits, labs) and Part D (medications).

Cardiovascular Risk

Patients with MASH have 2–3 times the cardiovascular mortality of the general population. Statins are the cornerstone of cardiovascular risk reduction in MASH — and contrary to an old clinical myth, statins are safe in MASH and are not contraindicated by elevated liver enzymes (unless baseline transaminases are more than three times the upper limit of normal). Part D covers statins at generic prices ($4–10/month). For cardiovascular coverage details, see the Medicare heart disease guide.

Weight Management

Weight loss of 7–10 percent of body weight reduces liver fat significantly and can achieve MASH resolution in some patients. Medicare covers:

• Intensive behavioral therapy for obesity (Part B, one visit per week for the first month, then monthly for the rest of year 1 — free, no deductible) for beneficiaries with a BMI ≥ 30
• Bariatric surgery (Part B/A) for beneficiaries with Class III obesity (BMI ≥ 40 or ≥ 35 with comorbidities)
• Weight management counseling as part of the annual wellness visit (no copay)

Surveillance for Hepatocellular Carcinoma

MASH is a direct precursor to hepatocellular carcinoma (HCC), and cirrhosis dramatically amplifies the risk. Patients with MASH cirrhosis (F4) should undergo HCC surveillance every six months with abdominal ultrasound ± AFP blood test — both covered under Part B. Patients with advanced fibrosis (F3) may also qualify for surveillance given the intermediate transition risk to cirrhosis.

If HCC is detected, Medicare covers the full range of treatments under Part B and Part A: surgical resection, radiofrequency ablation, transarterial chemoembolization (TACE), immunotherapy, and targeted agents. For a broader look at liver cancer treatment under Medicare, the Medicare cancer treatment guide covers the major modalities.

Liver Transplant for MASH Cirrhosis

When MASH progresses to decompensated cirrhosis — ascites, variceal bleeding, hepatic encephalopathy, spontaneous bacterial peritonitis — liver transplant may become the only curative option. As noted above, MASH has surpassed hepatitis C as the leading transplant indication in the United States.

Medicare covers liver transplant at a Medicare-approved transplant center:

• Part A covers the inpatient transplant surgery and hospital stay (subject to the $1,736 benefit-period deductible in 2026)
• Part B covers the pre-transplant evaluation, physician services, and outpatient follow-up
• Part D covers immunosuppressant drugs after transplant, with a 36-month limit for kidney transplant patients (different rule) — liver transplant patients retain indefinite Part D immunosuppressant coverage

For the complete transplant coverage rules, including the 2023 law that closed the immunosuppressant gap for kidney patients, see the Medicare organ transplant guide.

What MASH Costs Under Medicare: A Realistic Estimate

Here is what a Medicare beneficiary managing MASH with Rezdiffra can expect to pay annually (Original Medicare + Plan G Medigap):

Without Medigap, a hospitalization for a MASH complication (variceal bleeding, hepatic encephalopathy) would add the $1,736 Part A deductible per benefit period. Medigap Plan G covers that entirely after its one deductible. For a full comparison of Medigap plans, see the Medigap plans guide.

If costs are a barrier, Medicare Savings Programs can eliminate Part B premiums and cost-sharing entirely for low-income beneficiaries. The Medicare Savings Programs guide explains eligibility.

The Part B vs. Part D Split in MASH Management

MASH management straddles both parts of Medicare in ways that trip people up:

Understanding which part covers which service matters because Part B and Part D have separate deductibles, separate premium streams, and different coverage gaps. For a plain-language breakdown of how the two parts divide drug coverage, see the Part B vs. Part D drug coverage guide.

Steps to Navigate MASH Under Medicare

1. Confirm the diagnosis: If you have metabolic risk factors (diabetes, obesity, high triglycerides) and elevated liver enzymes, ask your primary care provider for a FIB-4 calculation and a FibroScan referral. Both are covered by Part B.
2. Get a hepatology referral: A hepatologist or transplant hepatologist should stage the fibrosis and determine if you meet criteria for Rezdiffra (F2–F3 biopsy-proven disease).
3. Check your Part D formulary: Before prescribing, your hepatologist should confirm that your specific plan covers Rezdiffra and what the PA requirements are. Medicare’s plan-finder tool lets you compare formularies.
4. Prepare for prior authorization: Bring biopsy results, FibroScan scores, FIB-4 calculations, and documentation of metabolic management to the PA submission. The more objective data included, the stronger the case.
5. Manage the metabolic cluster: Diabetes control (target HbA1c < 7%), statin therapy, blood pressure management, and structured weight loss all reduce fibrosis progression independent of Rezdiffra.
6. Enroll in HCC surveillance: If you have advanced fibrosis or cirrhosis, confirm with your hepatologist that you are on a six-month ultrasound schedule.
7. Review transplant eligibility proactively: If you have compensated cirrhosis, ask about listing criteria and which transplant centers are in-network under your Medicare plan.

Frequently Asked Questions

Does Medicare cover Rezdiffra (resmetirom)? Yes. Rezdiffra is covered under Medicare Part D as a specialty-tier drug. Most plans require prior authorization confirming biopsy-proven MASH at fibrosis stages F2–F3. With the $2,100 annual out-of-pocket cap (in effect since January 2025), the effective annual cost to most beneficiaries is under $2,100 regardless of list price.

Is MASH the same as fatty liver disease? MASH (or NASH) is the inflammatory form of fatty liver disease. Many people have MASLD — fat in the liver without significant inflammation. Only those with MASH, characterized by liver cell injury and inflammation alongside fat, face the elevated risk of fibrosis progression and liver failure. Diagnosis requires imaging and often biopsy to distinguish the two.

Does Medicare cover FibroScan? Yes. FibroScan (transient elastography, CPT 91200) is covered under Medicare Part B as a diagnostic imaging procedure. After the $283 Part B deductible, you pay 20 percent coinsurance — or nothing if you have Medigap Plan G.

Can Medicare cover bariatric surgery for MASH? Yes, if you meet the criteria: BMI ≥ 40, or BMI ≥ 35 with a serious obesity-related comorbidity such as Type 2 diabetes, hypertension, or sleep apnea. Weight loss through bariatric surgery is one of the most effective treatments for MASH and can achieve MASH resolution even without Rezdiffra.

What is the difference between MASH and hepatitis C for Medicare purposes? Both are serious liver diseases covered by Medicare, but they arise from different causes and are treated differently. Hepatitis C is a viral infection cured with 8–12 weeks of direct-acting antivirals (also under Part D, also at or below the $2,100 cap). MASH is metabolic — caused by obesity, diabetes, and insulin resistance — and is managed long-term rather than cured in a single course. For the hepatitis C coverage details, see the Medicare hepatitis C guide.

Will Medicare cover Rezdiffra for cirrhosis (stage F4)? Not yet — the current FDA approval is limited to fibrosis stages F2 and F3. Trials in compensated cirrhosis are ongoing. Coverage could expand if the FDA approves a broader indication; most Part D plans will follow the label. Patients with decompensated cirrhosis (ascites, bleeding, encephalopathy) should be evaluated for liver transplant.