The federal government, Centers for Medicare & Medicaid Services (CMS), allows Medicare Advantage (MA) organizations to limit enrollment in a plan to a predetermined number of enrollees, known as an enrollment capacity limit.
Key Logistics & Facts
Under federal regulations (42 CFR 422.254(c)(4) and 42 CFR 422.60(b), private Medicare Advantage insurance companies can cap enrollment, but they must follow strict requirements, including:
- Prior Approval via the Bid Process: An MA organization cannot arbitrarily stop accepting applications on the fly. They must request and disclose their enrollment capacity limit to CMS in advance during the annual plan bid submission process.
- Network & Health Safety Justification: Capacity limits are generally established when an insurer anticipates that surpassing a certain number of enrollees would strain its network adequacy, staffing, or operational capacity, potentially threatening beneficiary access to care.
- First-Come, First-Served Enforcement: Once a plan receives approval for a cap, CMS rules require the plan to process valid applications strictly in the chronological order they are received.
- Mandatory Plan Closure: Once the pre-approved capacity limit is reached, the plan must stop accepting prospective new enrollees for the remainder of that plan year. Any application received after reaching capacity must be denied in writing within 10 calendar days
Can a plan, after reaching its stated capacity level, limit new enrollments during the Annual Enrollment Period?
Yes. A Medicare Advantage (MA) plan that has a CMS-approved enrollment capacity limit can meet that cap and close to new enrollments during the Annual Enrollment Period (AEP).
If a plan reaches its predetermined capacity threshold before December 7th, CMS rules require it to immediately close to prospective new members, even if the open enrollment window is still active.
In practice, Medicare Advantage (MA) plans reaching their capacity limit and closing mid-enrollment is very rare. Out of more than 5,000 Medicare Advantage plans offered nationwide, only a tiny fraction (roughly 1% or around 65 plans) elect to set a CMS-approved enrollment capacity limit in their annual bid filings. The vast majority of MA plans operate with open, uncapped capacity.
Best Practice?
Verify open capacity directly with local carrier reps when enrolling late in Annual Enrollment Period.
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