How a January Enrollment Decides Who You Can Bill in February

5,865,920 Medicare beneficiaries have Part A and no Part B, the lowest share in the 162 months CMS has published. The file that dropped this morning shows where they went: since 2023 the column drains every January and February, and this year's drain was the biggest yet at 243,170 people. Here is the state-level spread your registration desk is working against, and the re-verification window it opens.

CMS refreshed the Medicare Monthly Enrollment file this morning, and the column nobody reads moved to a record.

5,865,920 people held Medicare Part A and no Part B in June 2026. That is 8.31% of everyone on Medicare, and it is the lowest that share has been in any of the 162 months CMS has published, going back to January 2013 (chart above). Six months earlier the same column held 6,182,265, an all-time high.

Part A-only is a derived number, not a published one. The file gives you everyone with Part A and everyone with both parts; the difference is the population whose Medicare card buys them a hospital stay and nothing your practice does in an office.

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