Metformin Medicaid Coverage by State Tier: 2026 Guide

Why there is no state tier table

A state-by-state table of metformin tiers, co-pays and prior-authorization criteria would need verified 2026 formulary data for each state. That data is not available here, so no table is shown and no state figure is given.

What the label establishes about metformin

Metformin is an oral biguanide, sold generically and by prescription only [1]. The immediate-release tablets are labeled as an adjunct to diet and exercise to improve glycemic control in adults and pediatric patients 10 years of age and older with type 2 diabetes [1]. The extended-release tablets are labeled for adults with type 2 diabetes only [2]. Prediabetes prevention, PCOS and weight loss are not labeled indications [1]. Metformin is also a component of combination products, including combinations with sitagliptin, glipizide, glyburide and empagliflozin; this page covers the single-ingredient drug [1].

Prediabetes and other off-label uses

Use of metformin in prediabetes, PCOS or weight loss is off-label, since the labeled indication is type 2 diabetes [1]. In the Diabetes Prevention Program, 3,234 adults with elevated fasting and post-load glucose were randomly assigned to placebo, metformin 850 mg twice daily, or an intensive lifestyle program. Over a mean 2.8 years, diabetes incidence was 11.0, 7.8 and 4.8 cases per 100 person-years, a 31% reduction with metformin versus placebo and 58% with lifestyle [3]. At 15 years of follow-up, the metformin reduction was 18% and the lifestyle reduction 27% [4].

What the prescribing information says about monitoring

The prescribing information for metformin hydrochloride tablets says to assess eGFR before starting and at least annually afterward [1]. It lists an eGFR below 30 mL/min/1.73 m2 as a contraindication, says starting is not recommended at 30 to 45, says to reassess benefit and risk if eGFR later falls below 45, and says to discontinue if it falls below 30 [1]. For iodinated contrast, the label says to stop metformin at the time of or before the procedure in patients with eGFR 30 to 60, a history of hepatic impairment, alcoholism or heart failure, or intra-arterial contrast, and to re-evaluate eGFR 48 hours afterward [1]. It also says to measure hematologic parameters annually and vitamin B12 every 2 to 3 years, and reports subnormal B12 in about 7% of patients in 29-week trials [1].