Medicare Enrollment and Medicare Advantage Share (CMS)

Limitations

Georgia and its 159 counties (where beneficiaries live), monthly from January 2013 to July 2026. The annual row (month = 'all', 2013-2025) is CMS's person-year figure, average monthly enrollment: not everyone enrolled during the year, and not December's count. 2026 is partial (January-July): monthly rows only, no 'all' row. pct_medicare_advantage is our calculation, num_beneficiaries_ma / num_beneficiaries, from CMS's published counts. Person-years are the months each beneficiary was enrolled during the calendar year, summed and divided by 12, so the annual row is never a sum of months, and someone enrolled part of the year can count partly in more than one category; never treat 2026's latest month or an average of its months as the year's figure. 'Medicare Advantage and other health plans' is CMS's category: Medicare Advantage plus other private health plans that CMS's data dictionary does not list (in CMS enrollment reporting the term usually covers plans such as Medicare cost plans and PACE), so it is not Medicare Advantage alone and can differ from Medicare Advantage-only counts. Original Medicare plus Medicare Advantage equals the total exactly on monthly rows and within 1 on annual rows (CMS rounds each person-year count). The total counts everyone with Medicare Part A, Part B or both, aged and disabled. CMS publishes sex, race, age and entitlement counts only for all beneficiaries, never split by Original Medicare and Medicare Advantage, so they are not in this table. From the July 2026 release. CMS publishes a new release each month that restates the whole series from January 2013, so earlier months can be revised and the figures here are replaced when the data is refreshed. CMS suppresses counts of 1-10 beneficiaries and counter-suppresses others so a suppressed count can't be recovered (shown as '*'); those cells are NULL here and are never filled in from other figures. A 0 is a real count. No served row has a suppressed count in this release. CMS's Unknown county (13999) is left out: it is not a county and CMS suppresses all of it, so the county rows need not add up to Georgia's state row (state minus the sum of counties: 0 to 3 on monthly rows and -13 to -1 on annual rows, from that and from rounding each place's person-years on its own). A county's change from December to January can partly reflect CMS reassigning beneficiaries' county of residence, not a change in enrollment (inferred, since CMS does not document it: the state total moves smoothly while neighboring counties step in opposite directions; from December 2023 to January 2024, for example, Catoosa lost 739 beneficiaries while Walker gained 709). Counts are of people enrolled, not events: the same people are counted in every month, so months never add up. tract_geoid is always NULL.