USPS currently participates in FEHBP, a program administered by OPM that offers a choice of health plan options to all postal and nonpostal federal employees and retirees. More than 140 health plans participate in FEHBP; these include fee-for-service plans and health maintenance organizations (HMO). The specific options available to enrollees depend on where one lives since fee-for-service plans are generally offered nationally while HMOs offer coverage in selected areas.