Medicare is the federal health insurance program for people 65 or older and certain younger people with disabilities. It is structured into Part A (hospital insurance), Part B (medical insurance), Part C (Medicare Advantage), and Part D (prescription drug coverage). Beneficiaries seeking coverage for prescription medications related to weight management frequently encounter a complex system of rules. While some drugs associated with weight loss can be covered, Medicare does not cover drugs prescribed solely for that purpose. Understanding the specific regulations governing Medicare Part D is the first step in determining what prescriptions are covered.
The Statutory Exclusion for Weight Loss Medications
Medicare Part D plans are legally prohibited from covering drugs used primarily for weight loss, weight gain, or anorexia. This exclusion is rooted in the Social Security Act ยง 1860D-2(e)(2)(A), which established the Part D benefit in 2003. The statute specifically excludes agents when used for anorexia, weight loss, or weight gain, regardless of whether the medications are prescribed for the treatment of obesity. Because of this federal mandate, a drug prescribed exclusively for chronic weight management will not be covered under a standard Part D plan. Medicare’s policy focuses on the prescribed use of the drug, meaning that even if a drug is FDA-approved for weight loss, it remains excluded if that is the only condition being treated.
Coverage Through Related Medical Conditions
The primary pathway for Medicare coverage of certain medications that cause weight loss is when they are prescribed for a different, non-excluded medical condition. Many of the newer medications, particularly the glucagon-like peptide-1 (GLP-1) receptor agonists, are approved by the Food and Drug Administration (FDA) for multiple indications. For example, a GLP-1 agonist approved for both Type 2 Diabetes and chronic weight management can be covered if the patient has a Type 2 Diabetes diagnosis.
Coverage is determined by the diagnosis code submitted with the prescription, which must align with an FDA-approved use that is not excluded under Part D. A medication like semaglutide, approved for Type 2 Diabetes, is covered when prescribed to manage blood sugar, even though significant weight loss may occur as a secondary effect. Some GLP-1 agonists have also received FDA approval for reducing the risk of major adverse cardiovascular events in patients with established heart disease, which qualifies them for Part D coverage. This means the plan covers the medication if prescribed for diabetes or cardiovascular risk reduction, but not if the prescription is written solely for weight loss.
Practical Steps for Determining Your Drug Costs
Since coverage for these dual-indication drugs is complex, the first practical step is to review the specific formulary for your Medicare Part D or Medicare Advantage (Part C) plan. The formulary is the list of drugs the plan covers, and coverage for specific medications can vary significantly between plans. You should confirm that the drug is on your plan’s formulary and note its cost-sharing tier, as higher tiers involve greater out-of-pocket costs.
Even if a drug is on the formulary, it may be subject to utilization management tools such as Prior Authorization (PA) or Step Therapy. Prior Authorization requires your healthcare provider to obtain approval from the plan by demonstrating that the medication is medically necessary for a covered indication, such as Type 2 Diabetes. Step Therapy requires you to try a less expensive, comparable medication first before the plan will cover the originally prescribed drug.
Your out-of-pocket costs will also depend on your plan’s cost-sharing structure, including deductibles and copayments or coinsurance. You must meet your plan’s annual deductible before coverage begins. Copayments are flat fees, while coinsurance is a percentage of the drug’s cost. In 2024, the Part D benefit includes a $2,000 yearly cap on out-of-pocket costs for covered drugs.