Though HMOs that used PBM-developed formularies increased from 10% of all HMO formularies in 2008 to 11.3% in 2009, 76.6% still develop their formularies internally. Health plans often outsource their formulary administration as a means for better benefit management.

Source: Sanofi Aventis, “Managed Care Digest Series, HMO-PPO Digest,” 2010–2011