UnitedHealth and Merck strike a deal to explore linking payments to drug performance By: CNBC.com News May 25, 2017 at 14:00 PM EDT UnitedHealth Group's Optum unit has signed a multiyear agreement with Merck to develop a better way to reimburse drugmakers. Read More >> Related Stocks: Aetna Cigna Corp Humana Merck & Co UnitedHealth Group