CMS Announces Additional Actions to Address Duplicate Enrollment

This article was exclusively distributed to subscribers on July 21, 2025. Click to receive additional information about how to subscribe and to activate a complimentary trial subscription.

On July 17, CMS a press release claiming that 2.8 million Americans were “either enrolled in Medicaid or the Children’s Health Insurance Program (CHIP) in multiple states or simultaneously enrolled in both Medicaid/CHIP and a subsidized Affordable Care Act (ACA) Exchange plan” and previewing future action by the agency to crack down on the incidence of duplicative enrollment. Per the announcement, an average of 1.2 million Americans were enrolled in Medicaid/CHIP in two or more states and an average of 1.6 million Americans were enrolled in both Medicaid/CHIP and a subsidized Marketplace plan each month.

Though CMS’ press release does not include data sources or methodology to validate its estimates, duplicate enrollment has been a persistent challenge for state Medicaid agencies and ACA Marketplaces. This issue reflects historically inadequate systems and data for identification, which were exacerbated during the COVID-19 public health emergency (PHE) bar on Medicaid disenrollment by the agency.

For Medicaid, states are statutorily required to conduct data matching through the Public Assistance Reporting Information System (PARIS), which has significant timeliness and automation limitations (i.e., does not provide any real-time data sources). (For more on PARIS and its limitations, see this authored by Manatt experts.) For ACA Marketplaces, individuals are not eligible for an advance payment of the premium tax credit (APTC) if they are enrolled in, or eligible for, Medicaid. While not an issue for state-based Marketplaces (SBMs) with integrated eligibility systems, the federally facilitated Marketplace (FFM, or HealthCare.gov) found significant issues with the quality and completeness of state data-sharing processes used to prevent duplicate enrollment during preparation for the PHE unwinding. CMS worked with state Medicaid agencies to come into compliance and relaunch an improved process to identify duplicate enrollment in late 2024, but some issues with data quality remain.

CMS’ announcement notes that the agency will undertake three initiatives to reduce duplicate enrollment:

1. CMS will provide states with a list of individuals who are enrolled in Medicaid/CHIP in two or more states and ask states to recheck Medicaid/CHIP eligibility for these individuals.
2. Consistent with current process, CMS will notify individuals enrolled in both Medicaid/ CHIP and an FFM plan to request that they: (1) disenroll from Medicaid/CHIP, if no longer eligible; (2) end their Marketplace APTC (with the option of ending their coverage); or (3) notify the FFM that the data match is incorrect and submit supporting documentation to show they are not enrolled in both Medicaid/CHIP and subsidized Marketplace coverage. After 30 days, the FFM will end the subsidy for individuals who still appear to be enrolled in both Medicaid/CHIP and a subsidized Marketplace plan.
3. CMS will provide SBMs with a list of individuals who are potentially enrolled in Medicaid/CHIP and a subsidized Marketplace plan and ask SBMs to determine whether these individuals are dually enrolled. If so, CMS directs SBMs to implement a process similar to that of the FFM in order to verify eligibility.

In order to execute these plans, CMS has promised additional guidance in early August “with expectations for tackling concurrent enrollment.”

Additionally, the press release notes that CMS will continue work to stand up the policy enacted in the recent reconciliation legislation requiring states to establish standardized processes to regularly update address information for Medicaid and CHIP enrollees (by January 1, 2027) and to establish a new federal database to identify individuals simultaneously enrolled in Medicaid in more than one state (by October 1, 2029).

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