Key Data Findings. (1) From March 2012 to March 2013, rural enrollment in Medicare Advantage (MA) and other prepaid plans increased by over 200,000 enrollees, to more than 1.9 million. (2) Preferred provider organization (PPO) plan enrollment increased to nearly one million enrollees, accounting for more than 51% of the rural MA market (up from 48% in March 2012). (3) Health maintenance organization (HMO) enrollment continued to grow in 2013, with over 31% of the rural MA market, while private fee-for-service (PFFS) plan enrollment decreased to less than 10% of market share. (4) Despite recent changes to MA payment, rural MA enrollment continues to increase.