Abstract Body: Background: Use of antihypertensive single-pill combinations (SPC) – which are guideline-recommended to improve adherence and reduce clinical inertia – is declining among Medicaid patients, underscoring the need to ensure adequate drug therapy for these vulnerable populations. Preferred drug lists (PDLs) are designed to help Medicaid programs promote use of lower cost, effective drugs, and inclusion of SPCs on PDLs could improve access.

Objective: Describe antihypertensive SPC coverage within fee-for-service (FFS) Medicaid programs.

Methods: In May 2025, we extracted the PDLs for FFS Medicaid programs in 50 US states and the District of Columbia. Each PDL was evaluated for coverage of the 27 antihypertensive SPCs available in the US as of May 2025. Coverage was dichotomized as covered vs. not covered at the class level (e.g., beta-blocker/thiazide) and the individual product level (e.g., atenolol/chlorthalidone vs. bisoprolol/hydrochlorothiazide). A product was categorized as not covered if it was missing from the PDL, explicitly noted to be non-preferred, or required prior authorization or step therapy.

Results: Among 51 programs, an average of 15 SPCs were covered (range 5-24), with coverage of each product varying by state (Figure). Every Medicaid program covered at least one renin-angiotensin-system (RAS) blocker + thiazide SPC. Of the 13 available RAS + thiazide SPCs, an average of 8 were covered (range 4-12), with universal coverage of losartan/HCTZ across all programs. All programs except two covered at least one RAS blocker + calcium channel blocker (CCB). No program covered the RAS blocker + beta-blocker SPC nebivolol/valsartan. Only 22 (43%) programs covered spironolactone/HCTZ. Triple therapy SPCs (i.e., RAS blocker + thiazide + CCB) were covered by 29 programs (57%).

Conclusions: Although US FFS Medicaid programs vary in their coverage of specific SPC products, at the class level, nearly all programs offer sufficient coverage to ensure that members receive first-line guideline-recommended treatment (RAS blocker, CCB, and/or thiazide diuretic). Nonetheless, gaps remain to ensure equitable coverage of SPC products that could be advantageous for patients with resistant hypertension (i.e., spironolactone/HCTZ) or to optimize adherence with triple therapy. These gaps potentially limit treatment optimization and could contribute to clinical inertia in vulnerable populations.