Medicare Open Enrollment Period: Rules, Dates & Checklist

The Medicare Advantage Open Enrollment Period (MA OEP) gives people who are already enrolled in a Medicare Advantage plan a limited opportunity to reconsider that coverage.

The annual MA OEP runs January 1 through March 31. During this period, an eligible beneficiary can make one change: switch to another Medicare Advantage plan or leave Medicare Advantage and return to Original Medicare. If the beneficiary returns to Original Medicare, they may also be able to join a stand-alone Medicare drug plan. Changes generally take effect the first day of the month after the plan receives the request.

For insurance agents, OEP is less about creating another sales season and more about being prepared to respond appropriately when clients have questions about their coverage. CMS places specific restrictions on knowingly targeting Medicare Advantage enrollees with unsolicited OEP marketing, so agents need to understand both the enrollment rules and the marketing boundaries.

This guide brings those pieces together: who can use MA OEP, what changes are permitted, what agents should avoid, and how to prepare for client-initiated conversations.

What Is the Medicare Advantage Open Enrollment Period?

The Medicare Advantage Open Enrollment Period is an enrollment window for people who are already enrolled in a Medicare Advantage plan.

For existing Medicare Advantage members, the annual period runs:

January 1 through March 31

During MA OEP, a beneficiary can:

• Switch from one Medicare Advantage plan to another Medicare Advantage plan, with or without prescription drug coverage.
• Drop a Medicare Advantage plan and return to Original Medicare.
• Join a stand-alone Medicare drug plan when returning to Original Medicare, when applicable.

A beneficiary generally gets one change during the annual MA OEP, and the change becomes effective on the first day of the month after the plan receives the enrollment request.

MA OEP does not give everyone with Medicare a general opportunity to change coverage. The beneficiary must already be enrolled in Medicare Advantage to use the annual MA OEP.

What Clients Cannot Do During MA OEP

Understanding what OEP does not allow is just as important as understanding what it does.

During the annual Medicare Advantage OEP, a beneficiary generally cannot use the OEP to:

• Move from Original Medicare into a Medicare Advantage plan.
• Join a stand-alone Medicare drug plan while remaining in Original Medicare solely because it is MA OEP.
• Switch from one stand-alone Medicare drug plan to another using the MA OEP.
• Make repeated Medicare Advantage changes throughout the January 1–March 31 period.

Those situations may require another valid enrollment period, such as the Annual Enrollment Period or an applicable Special Enrollment Period. Medicare.gov maintains current information about the enrollment opportunities available for different circumstances.

Agents who want a broader refresher can review PSM’s Medicare Enrollment Periods Explained: IEP, AEP, OEP and SEPs.

What About Clients Who Are New to Medicare?

There is also an MA OEP opportunity for some beneficiaries who are new to Medicare and enroll in Medicare Advantage.

Medicare.gov explains that if a beneficiary joins a Medicare Advantage plan when first becoming eligible for Medicare, the opportunity runs from the first month the person has both Medicare Part A and Part B through the last day of the third month they have both.

During this period, an eligible beneficiary may:

• Switch to another Medicare Advantage plan, with or without prescription drug coverage.
• Leave Medicare Advantage and return to Original Medicare.
• Obtain stand-alone Medicare drug coverage when returning to Original Medicare, when applicable.

Because timing can vary based on the beneficiary’s Medicare effective dates, agents should verify the applicable enrollment period before submitting an application.

Medicare AEP vs. OEP: What's the Difference?

The Annual Enrollment Period and Medicare Advantage Open Enrollment Period are often confused, but they serve different purposes.

During AEP, beneficiaries have a broader range of Medicare health and drug plan changes available. MA OEP is narrower and is specifically designed for qualifying Medicare Advantage enrollees. Medicare’s annual October 15–December 7 Open Enrollment changes generally take effect January 1.

For a more detailed comparison, see Medicare AEP vs. OEP: Understanding the Medicare Enrollment Periods.

Why Might a Client Contact an Agent During OEP?

A client may discover after January 1 that their Medicare Advantage plan is not working as expected.

Common concerns can include:

• A preferred doctor or specialist is not in the plan’s network.
• A prescription is covered differently than expected.
• The client misunderstood a copayment, deductible, or other cost-sharing requirement.
• A pharmacy is not preferred or is outside the network.
• The client has questions about prior authorization or referral requirements.
• The client is having difficulty using a supplemental benefit.
• The client has relocated or experienced another change that may affect plan availability.
• The client simply does not understand how the new coverage works.

The first step should not automatically be a plan change.

Sometimes the appropriate response is helping the client understand or use the coverage they already have. In other cases, after reviewing the client’s situation and applicable enrollment rights, another option may warrant consideration.

Use a Coverage Review Before Discussing a Change

When a client proactively contacts you with concerns, a structured coverage review can help identify the actual problem.

Consider reviewing:

Providers

Are the client's physicians, specialists, hospitals, and other important providers participating in the plan’s current network?

Prescription drugs

Review:

• Current prescriptions.
• Formulary status.
• Drug tier.
• Pharmacy network.
• Prior authorization requirements.
• Step therapy or quantity limits when applicable.

Costs

Discuss the costs relevant to the client's actual usage, which may include:

• Premium.
• Deductible.
• Copayments.
• Coinsurance.
• Maximum out-of-pocket amount for applicable medical services.

Plan rules

Make sure the client understands plan requirements such as:

• Network rules.
• Referrals.
• Prior authorization.
• Out-of-network coverage, when applicable.

Supplemental benefits

If supplemental benefits are important to the client, verify the current plan's benefit details, eligibility, limitations, and service area rather than relying on assumptions or prior-year information.

Benefits and availability vary by plan and market.

Be Careful When a Client Wants to Return to Original Medicare

Leaving Medicare Advantage for Original Medicare can have consequences beyond the immediate MA disenrollment.

One important consideration is Medicare Supplement insurance, or Medigap.

Returning to Original Medicare does not automatically mean a beneficiary can purchase any Medigap policy they want without underwriting. Federal guaranteed-issue rights apply in certain situations, including some trial-right circumstances, but eligibility depends on the beneficiary's specific situation. State protections can also differ. Medicare.gov advises beneficiaries to review their Medigap rights before making a coverage change.

Agents should therefore avoid treating an MA-to-Original-Medicare change as a simple two-step transaction.

Before a client makes that decision, verify:

• Whether the client has a Medigap guaranteed-issue right.
• Applicable state rules.
• Available Medigap policies.
• Prescription drug coverage needs.
• Effective dates.
• Any underwriting requirements that may apply.

MA OEP Marketing Rules Agents Need to Know

MA OEP has specific marketing restrictions.

Current federal regulations prohibit Medicare Advantage organizations from knowingly targeting or sending unsolicited marketing materials to MA enrollees during OEP. The regulation also prohibits activities intended to target OEP as an opportunity to generate further sales.

Examples of prohibited OEP targeting include:

• Sending unsolicited materials promoting the opportunity to make another enrollment change or specifically referencing OEP.
• Purchasing or using lists to specifically identify beneficiaries who are in OEP because of an AEP enrollment decision.
• Promoting agent or broker activity intended to target the OEP as another sales opportunity.
• Contacting former enrollees who selected a different plan during AEP for the purpose described by the regulation.

The rules do, however, allow certain activities when the beneficiary initiates the interaction. For example, the regulation permits providing marketing materials when a beneficiary proactively requests them and permits beneficiary-requested one-on-one meetings with sales agents. It also permits educational information about the existence of OEP on an MA organization's website, provided the material is educational rather than marketing.

Agents should also follow applicable carrier requirements, CMS guidance, consent rules, and their organization’s compliance procedures.

For broader guidance, review PSM’s Compliance Best Practices for Licensed Insurance Agents and Medicare Communication & Marketing Guidelines for Insurance Agents.

Educational Communication vs. OEP Sales Targeting

A useful way to think about OEP communication is to distinguish education and client service from targeted OEP solicitation.

Educational communication may help beneficiaries understand:

• What MA OEP is.
• When it occurs.
• General Medicare enrollment periods.
• How Medicare Advantage works.
• Where beneficiaries can obtain Medicare information.

That is different from sending an unsolicited message to a known MA enrollee telling them that OEP gives them another chance to switch plans.

When in doubt, review the communication against current CMS regulations, applicable carrier requirements, and your compliance process before distributing it.

PSM agents can also explore the PSM Marketing Hub for no-cost marketing resources and support.

Medicare OEP Agent Checklist

Use this checklist before and during OEP to keep your client-service process organized.

Review and prepare

• Review current CMS OEP enrollment and marketing requirements.
• Review carrier-specific procedures and requirements.
• Confirm that enrollment tools and carrier certifications are current.
• Update client records and contact information where appropriate.
• Make sure plan-year materials and benefit information are current.
• Review your process for documenting beneficiary requests and interactions.

Educate without creating improper OEP solicitation

• Make enrollment-period education part of your broader Medicare education strategy.
• Use neutral educational explanations of OEP rather than positioning it as another sales season.
• Do not send unsolicited OEP-specific marketing to beneficiaries prohibited by the applicable CMS rules.
• Review social, email, direct-mail, and digital campaigns for OEP references before publication.

When a beneficiary proactively contacts you

• Identify the concern before discussing a change.
• Confirm that the beneficiary has a valid enrollment opportunity.
• Review providers, prescriptions, costs, plan rules, and other priorities.
• Verify current plan details rather than relying on prior-year information.
• Explain relevant trade-offs clearly.
• Confirm applicable effective dates.
• Document the interaction according to your agency, carrier, and compliance procedures.

Before submitting an enrollment

• Verify eligibility for the election period being used.
• Confirm plan availability in the beneficiary's service area.
• Confirm providers and pharmacies when relevant.
• Review prescription drug coverage when applicable.
• Complete required disclosures and enrollment documentation.
• Follow applicable Scope of Appointment procedures.
• Follow current call-recording requirements when applicable.
• Retain required records according to current CMS, carrier, and organizational requirements.

For additional guidance on telephone-based Medicare activity, see PSM’s Call Recording and Retention Requirements for Medicare Sales.

Common OEP Mistakes Agents Should Avoid

Treating OEP like a second AEP

MA OEP is a limited enrollment opportunity, not a repeat of the Annual Enrollment Period.

Assuming every dissatisfied beneficiary should change plans

A service issue may be resolved without changing coverage. Diagnose the problem first.

Using outdated benefit information

Medicare Advantage benefits, provider networks, formularies, costs, and plan availability can change. Verify current information for the applicable plan and service area.

Overlooking Medigap implications

A beneficiary returning to Original Medicare may not automatically have unrestricted access to Medigap coverage. Review applicable rights before the client makes the change.

Initiating prohibited OEP marketing

Do not treat January through March as an opportunity to specifically target MA enrollees for additional sales. Current federal regulations place explicit restrictions on OEP targeting.

Failing to document the client's request

As an operational best practice, maintain clear records showing how an interaction began, what the beneficiary requested, what information was reviewed, and what action was taken.

Frequently Asked Questions About Medicare OEP

When is the Medicare Advantage Open Enrollment Period?

For beneficiaries already enrolled in Medicare Advantage, the annual MA OEP runs January 1 through March 31.

Who can use Medicare Advantage OEP?

The annual MA OEP is generally available to beneficiaries who are already enrolled in a Medicare Advantage plan. A separate MA OEP opportunity also applies to certain beneficiaries who are new to Medicare and initially enroll in Medicare Advantage.

How many changes can a beneficiary make during MA OEP?

Medicare states that a beneficiary can make one change during the Medicare Advantage Open Enrollment Period.

When does an OEP plan change take effect?

A Medicare Advantage OEP change generally takes effect on the first day of the month after the plan receives the enrollment request.

Can someone switch from Original Medicare to Medicare Advantage during MA OEP?

No. The annual MA OEP does not allow someone in Original Medicare to use that enrollment period to join Medicare Advantage. Another valid enrollment opportunity would be required.

Can someone leave Medicare Advantage during OEP?

Yes. An eligible Medicare Advantage enrollee can use MA OEP to return to Original Medicare and, when applicable, enroll in a stand-alone Medicare drug plan.

Can agents advertise OEP to Medicare Advantage members?

Agents need to be cautious. Federal regulations prohibit knowingly targeting or sending unsolicited OEP marketing to MA enrollees and prohibit certain activities designed to turn OEP into another sales opportunity. Beneficiary-requested interactions and certain educational communications are treated differently.

OEP Is an Opportunity to Provide Better Client Service

For independent Medicare agents, the strongest OEP strategy is not aggressive outreach. It is preparation, responsiveness, accurate plan review, and compliant client service.

Know the enrollment rules. Keep current plan information available. Understand the marketing restrictions. Build a consistent process for reviewing client concerns before recommending a change.

Agents who want additional support with Medicare products, contracting, training, compliance guidance, enrollment technology, and marketing resources can explore PSM’s Medicare solutions for independent agents.

Sources

• Medicare.gov — Joining a Medicare health or drug plan
• Medicare.gov — Understanding Medicare Advantage & Medicare Drug Plan Enrollment Periods
• eCFR — 42 CFR § 422.2263, Medicare Advantage marketing requirements
• CMS — Medicare Marketing Guidelines
• Medicare.gov — Medigap enrollment rights

For agent use only. This article provides general educational information and is not legal advice. Medicare requirements, carrier procedures, plan availability, benefits, and compliance guidance can change. Agents should verify current requirements with CMS, applicable carriers, state regulators, and their compliance resources before acting.