​​Full and Partial Dual Eligibility

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Individuals dually eligible for both Medicare a​​​​nd Medi-Cal are known as “dual eligibles" or “Medi-Medis."  The population of dual eligibles in California includes key groups below. 

Full Duals

“Full duals" are members who are enrolled in Medicare Parts A, B, and D, and Medi-Cal. Almost all of the 1.7 million dual eligible members in California are enrolled as full duals.  Since these members are enrolled in Medicare Parts A and B, they may enroll in Medicare Advantage plans (including Dual Eligible Special Needs Plans, or D-SNPs).  Full duals are entitled to full-scope Medi-Cal benefits, including coverage for Medicare cost sharing such as Medicare premiums and copays. Additionally, Medi-Cal covers benefits not provided by Medicare, such as long-term services and supports, dental and vision.  Full duals are enrolled in Medi-Cal managed care plans.  Medicare providers may not bill full duals for Medicare Parts A and B cost sharing.

Medicare Partial-Benefit Duals

The federal Centers for Medicare &Medicaid Services (CMS)​​ defines partial-benefit duals or “partial duals" as members enrolled in one of several Medicare Savings Programs (MSPs), with Part A and/or Part B coverage, but not enrolled in Medi-Cal.  MSP enrollment for this group means that DHCS covers their Part A and/or Part B cost sharing, but they are not enrolled in Medi-Cal and do not receive full Medi-Cal benefits.  Partial-benefit duals with Part A and B coverage, but not Medi-Cal coverage, are eligible to enroll in Medicare Advantage plans but not D-SNPs.  These members are not enrolled in Medi-Cal managed care plans. Partial duals can be in QMB, SLMB, and QI, but are not QMB+, SLMB+, or full-benefit dual. In California there are relatively few partial-benefit duals, as the income limit for most MSPs in California is similar to the Medi-Cal income limit, and most individuals enrolling in MSPs also choose to also enroll in Medi-Cal and get full benefits.  Medicare providers may not bill partial-benefit duals for Medicare Part A and B cost sharing.​​​​​ Individuals may apply for what they want (either Medi-Cal + Medicare Saving Program (MSP) or just MSP).

​Part B Only​

Part B only includes members enrolled in Medicare Part B only (but not Part A) and Medi-Cal.  The Part A Buy-In policy transitioned most of these members to full duals as of January 1, 2025.  The remaining Part B only members includes those​ not QMB eligible.  Members with Medicare Part B only and Medi-Cal are enrolled in Medi-Cal managed care plans.  Medicare providers may not bill Part B only members with Medi-Cal for Medicare Part B cost sharing.

Note:  If a full dual loses Medi-Cal (e.g., due to income increase or missing paperwork), they do not automatically become a partial dual, unless they have requested an evaluation for MSP only. Counties perform an annual redetermination for both Medi-Cal and Medicare. There is no situation where a member would lose Medi-Cal Eligibility and keep MSP without a special request.

​​Medicare Part A Buy-In Agreement

As of January 1, 2025, the State of California participates in a buy-in agreement with the CMS, whereby Medi-Cal automatically pays Medicare Part A premiums, coinsurance, and deductibles for Medi-Cal members who:

Additional Informational Resources​

Medicare Savings Programs in California

Integrated Care for Dual Eligible Beneficiaries