"A Pfizer spokesman declined to comment on the reasons for CVS’s decision. He said Viagra continues to be available to millions of patients including to certain CVS plan members. Viagra’s price varies by pharmacy and dosing strength; it sells for at least $40 a pill at many U.S. pharmacies, according to GoodRx Inc., which tracks prescription prices. U.S. Viagra sales rose 15% to $605 million for the first six months of 2015.

Express Scripts says it expects the exclusions to force fewer than 0.5% of plan members to switch drugs."

http://www.wsj.com/articles/drug-plan-managers-wield-potent-weapon-1438905295