 This number varies yearly as new sponsors apply to CMS and/or old ones drop out (a process that takes place between January and June of the preceding year).In the 1970s, less than a decade after the beginning of fee for service (FFS) "Original Medicare," Medicare beneficiaries gained the option to receive their Medicare benefits through managed, capitated health plans, mainly HMOs, as an alternative.But initially this choice was only available under temporary Medicare demonstration programs.