Navigating Mounjaro Insurance Approval: Criteria for Private & Medicare Plans

Access to Mounjaro (tirzepatide) has become a significant logistical challenge, not just due to supply chain constraints, but due to increasingly rigid payer criteria. For patients and providers, understanding the specific utilization management protocols used by Pharmacy Benefit Managers (PBMs) is essential to securing approval.

Insurance coverage is rarely automatic for this class of medication. Whether you are dealing with a commercial plan, a self-insured employer, or Medicare, approval hinges on meeting strict clinical guidelines regarding diagnosis codes and step therapy.

The FDA Label vs. Payer Policy

The single most important factor in insurance approval is the FDA indication.

Mounjaro is FDA-approved specifically for Type 2 Diabetes Mellitus (T2D). While it is frequently prescribed off-label for weight management, most insurers strictly segregate coverage based on ICD-10 codes.

• ICD-10 Code E11.9 (Type 2 Diabetes): This is the standard gateway for Mounjaro coverage.
• ICD-10 Code E66.9 (Obesity): If this is the primary diagnosis, payers will typically deny Mounjaro and redirect to Zepbound (the same molecule, approved for obesity) or deny coverage entirely if the plan excludes anti-obesity medications (AOMs).

Private Insurance & Criteria

Commercial insurers (e.g., United HealthCare (UHC), BlueCross BlueShield (BCBS), Aetna, Cigna) generally place Mounjaro on Tier 2 or Tier 3 of their drug formularies. Approval almost always triggers a Prior Authorization (PA) requirement.

Common PA Requirements

To approve the claim, PBMs generally require documentation of the following:

Employer-Sponsored Plans

Many individuals are surprised to find their coverage denied even if they meet medical criteria. This is often due to the structure of Self-Funded Employer Plans.

Large employers often "self-insure," meaning they pay claims directly and simply hire an insurance company to act as an administrator. These employers have the legal right to exclude entire categories of drugs to control costs.

• The GLP-1 Exclusion: Many employers are currently adding exclusions for GLP-1 agonists used for weight loss, and some are restricting them strictly to T2D with high copays.
• Check the Formulary: Before seeking a prescription, review your employer’s specific "Exclusion List." If GLP-1s are excluded, a standard appeal is rarely successful; it requires a request for a formulary exception based on medical necessity.

Medicare Advantage & Part D

Medicare coverage is governed by strict federal statutes regarding weight loss drugs.

The Statutory Ban

Under current law, Medicare Part D is prohibited from covering drugs used solely for weight loss. Therefore:

• For Obesity: Medicare will generally not cover Mounjaro (or Zepbound) if the only diagnosis is obesity.
• For Type 2 Diabetes: Medicare Part D and Medicare Advantage plans do cover Mounjaro, provided it is medically necessary for T2D management.

Beneficiaries in Medicare Advantage plans may face stricter Step Therapy protocols than traditional Medicare, often requiring a trial of not just Metformin, but also a Sulfonylurea or an older GLP-1 (like Trulicity or Victoza) before Mounjaro is authorized.