This study evaluated the specialty pharmacist's role in medication access, treatment monitoring, and reducing maribavir waste. Pharmacists facilitated maribavir access by obtaining timely insurance prior authorizations (median = 1 day) and intervened to reduce 28 fills across 94 dispenses to avoid waste. Maribavir quantity was reduced in 10 dispenses during the final treatment course, based on CMV levels and time until next lab appointment, which resulted in $119,517 - $149,396 in avoided costs.