OBJECTIVES: To assess the financial consequence to a US health plan’s direct pharmacy budget when EBR/GZR is added to the formulary for the treatment of G1 and 4 CHC patients. METHODS: The budget impact model (BIM) compared two scenarios, without EBR/GZR (scenario 1) and with (scenario 2) EBR/GZR on the formulary. The impact of the addition of EBR/GZR to the formulary was assessed within the context of other FDA-approved treatments for CHC G1 and 4 infection, which were assumed to be on formulary. Regimens and treatment durations were assumed to follow FDA-approved labeling and differed by genotype, presence of cirrhosis, and presence of chronic kidney disease (CKD) stage 4/5. Costs included medication wholesale acquisition costs and RAV testing, and were calculated over a 3-year time horizon. The incremental pharmacy cost of adding EBR/GZR to the formulary was estimated by calculating the total and per-member-per-month (PMPM) costs, with or without EBR/GZR in patients with and without CKD. RESULTS: Using an assumed plan size of 4,000,000 members, it was estimated that 11,465 patients with G1 or 4 CHC would be treated over 3 years. The total cumulative direct pharmacy budget was estimated at $1,062,307,272 (scenario 1) without EBR/GZR, and $1,002,922,056 after adding EBR/GZR to the formulary (scenario 2), a reduction of $59,385,216 (5.59%) over 3 years. PMPM cost decreased from $7.38 to $7.16 (-3.00%) in year 1, $6.94 (-5.87%) in year 2, and $6.79 (-7.90%) in year 3. In CKD stage 4/5 patients, total direct pharmacy budget was estimated at $14,930,787 (scenario 1) before adding EBR/GZR and $14,871,236 after adding EBR/GZR to the formulary (scenario 2), a 0.40% reduction. CONCLUSIONS: Based on the inputs and assumptions used in the BIM, the introduction of EBR/GZR to the formulary was projected to be cost savings to direct pharmacy budget of a health plan over a 3-year period.