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CMS Medicare enrollment · April 2026

California Medicare Enrollment

State and county enrollment from CMS, including Original Medicare, Medicare Advantage and Other Health Plans, and Part D coverage.

Informational only. These enrollment counts do not compare plans or provide medical, financial, or enrollment advice.

Total Medicare enrollment
7.2M

7,211,841

Original Medicare
3.5M

3,498,679 beneficiaries

MA & Other share
51.5%

CMS combined delivery-system measure

Part D coverage
84.4%

6,084,636 beneficiaries

County enrollment

59 CMS county rows for California. Unavailable values remain marked as not reported rather than estimated.

CountyTotalOriginal MedicareMA & OtherMA & Other sharePart D share
Alameda County277,446131,726145,72052.5%84.9%
Alpine County2842394515.8%77.8%
Amador County12,4938,5293,96431.7%81.3%
Butte County48,79042,7446,04612.4%80%
Calaveras County14,46011,7282,73218.9%78.3%
Colusa County4,2903,9443468.1%80.5%
Contra Costa County228,184109,621118,56352%83.8%
Del Norte County6,7126,3373755.6%79.5%
El Dorado County52,29630,17922,11742.3%82.8%
Fresno County161,20383,03878,16548.5%83.8%
Glenn County5,9965,5434537.6%78.9%
Humboldt County31,25728,4442,8139%78.9%
Imperial County37,50623,24914,25738%81.9%
Inyo County4,7584,15360512.7%78.2%
Kern County135,02970,95864,07147.4%85.1%
Kings County19,71812,2637,45537.8%79.2%
Lake County17,88915,4372,45213.7%77.6%
Lassen County5,5764,99558110.4%77.3%
Los Angeles County1,707,013729,495977,51857.3%86.6%
Madera County27,35713,72013,63749.8%83.7%
Marin County64,79035,52629,26445.2%85.4%
Mariposa County5,1424,27087217%73.5%
Mendocino County24,22021,1053,11512.9%79.5%
Merced County43,16830,41612,75229.5%81.8%
Modoc County2,6072,4601475.6%75.3%
Mono County2,1501,9432079.6%75.5%
Monterey County74,74862,09312,65516.9%76.3%
Napa County32,19917,34714,85246.1%84.5%
Nevada County31,32224,7666,55620.9%80.4%
Orange County603,122266,755336,36755.8%86.6%
Placer County102,03644,52557,51156.4%85.5%
Plumas County6,5105,75775311.6%76.4%
Riverside County452,145166,474285,67163.2%85.8%
Sacramento County294,658111,641183,01762.1%86.5%
San Benito County11,2329,0012,23119.9%76.3%
San Bernardino County349,071114,087234,98467.3%86.4%
San Diego County622,423289,032333,39153.6%80.5%
San Francisco County159,38977,61381,77651.3%86.4%
San Joaquin County128,71458,23670,47854.8%84.9%
San Luis Obispo County73,96155,96617,99524.3%82.5%
San Mateo County143,20170,33772,86450.9%82.4%
Santa Barbara County86,28668,76117,52520.3%79.7%
Santa Clara County312,175155,027157,14850.3%81.7%
Santa Cruz County59,91744,93414,98325%82%
Shasta County49,21445,1444,0708.3%76.4%
Sierra County90578312213.5%75.7%
Siskiyou County14,03013,3137175.1%76.7%
Solano County92,51041,23151,27955.4%78.7%
Sonoma County122,09257,16764,92553.2%86.1%
Stanislaus County96,31140,61955,69257.8%87.4%
Sutter County18,71016,9281,7829.5%76.2%
Tehama County14,86713,2391,62811%76.5%
Trinity County3,6523,4911614.4%78.3%
Tulare County70,87044,43626,43437.3%84.8%
Tuolumne County16,58314,4012,18213.2%77.1%
UnknownNot reportedNot reportedNot reportedNot reportedNot reported
Ventura County177,135104,15072,98541.2%82.8%
Yolo County37,16718,09719,07051.3%85.6%
Yuba County14,34611,2603,08621.5%75.6%

Source and interpretation

CMS Medicare Monthly Enrollment, April 2026, published 2026-07-23. “MA & Other” retains the official combined CMS field label.

  • CMS suppresses some small counts with an asterisk; suppressed values remain null in this snapshot.
  • Medicare Advantage and Other Health Plans is the CMS-published combined measure and is not limited to Medicare Advantage alone.
  • Enrollment counts describe a reporting month and do not compare plan benefits, provider networks, quality, or personal costs.

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