Medicare AdvantagePrior AuthMedium impact
Biguanide Agents (Revised)
Humana·Endocrinology, Family Medicine, General Practice +2 more·Medicare Advantage
Effective date
Jan 1, 2019
We identified it
Jun 25, 2026
Summary
Humana Medicare Advantage updated its Biguanide Agents (metformin) pharmacy coverage policy effective January 1, 2019, with a revision dated October 22, 2025. This is a step therapy policy requiring members to have at least 3 months of prior treatment or documented intolerance to metformin IR (500mg, 850mg, or 1000mg) or metformin ER before approval for Glumetza, metformin 625mg, or other metformin ER formulations. Approvals are granted for plan year durations or as determined through clinical review.
Action Required
By November 15, 2025: Billing and prior authorization teams must ensure all requests for Glumetza, metformin 625mg, and metformin ER products in Medicare Advantage plans are screened against the step therapy requirement. Verify in member records or request from providers documentation of: (1) at least 3 months prior treatment with metformin IR (500mg, 850mg, or 1000mg) or metformin ER, OR (2) documented intolerance to these agents. Update prior authorization templates and clinical review workflows to enforce this criterion. Routes claims for these products without documented step therapy completion to medical review for denial. Educate providers and billing staff that claims lacking evidence of prior metformin IR/ER trial will be rejected and require additional documentation before resubmission.