Medicare Advantage Open Enrollment Period (OEP)

The Medicare Advantage Open Enrollment Period (OEP) is a period during which Medicare beneficiaries who are enrolled in a Medicare Advantage Plan can make changes to their coverage. It occurs annually from January 1 to March 31.

During the OEP, beneficiaries who are enrolled in a Medicare Advantage Plan can make the following changes to their coverage:

• Switch to a different Medicare Advantage Plan: Beneficiaries can switch to a different Medicare Advantage Plan that has a 5-star rating or enroll in a different Medicare Advantage Plan that is available in their service area.

• Drop their Medicare Advantage Plan and return to Original Medicare: Beneficiaries can also drop their Medicare Advantage Plan and return to Original Medicare. They can also enroll in a standalone Medicare Part D prescription drug plan.

It's important to note that the OEP is different from the Annual Enrollment Period (AEP), which occurs from October 15 to December 7 each year. During the AEP, beneficiaries can switch from Original Medicare to a Medicare Advantage Plan, switch from one Medicare Advantage Plan to another, or enroll in a Medicare Part D prescription drug plan.

Also, not all beneficiaries are eligible for the OEP. Those who are already enrolled in Original Medicare with a standalone Medicare Part D prescription drug plan are not eligible. The OEP is only available to those who are enrolled in a Medicare Advantage Plan.

Next Up

This month, Catalyst makes prospecting and outreach easier with AI-powered email creation, more powerful search filters, improved industry and Workers' Comp data, broader access to Mployer data through AI assistants, and improvements to Advanced Analytics.
According to Mployer Insights’ 2026 analysis of 76,000+ employer benefit plans, basic group life insurance achieves near-universal participation with an 83% employer offer rate and a 97% employee enrollment rate, driven by the fact that 96% of basic plans are noncontributory (100% employer-paid). While 47% of employers structure life insurance as a variable multiple of earnings—with 1x salary serving as the dominant national standard (62% of multiple-based plans)—flat-dollar benefit options vary widely from $8,500 (10th percentile) to $48,793 (90th percentile). Additionally, 92% of employers offer employee-paid voluntary life insurance to allow workers to bridge the gap toward the recommended 10–12x salary coverage target.
According to Mployer Insights’ 2026 analysis of 76,000+ employer benefit plans, disability insurance remains a major market differentiator, with only 41% of U.S. employers offering short-term disability (STD) and 38% offering long-term disability (LTD). While 60% salary replacement serves as the national standard across both benefit types, standard plan designs disproportionately expose higher earners due to median benefit caps of $1,602/week for STD and $8,273/month for LTD. Furthermore, alignment between STD benefit durations (median 26 weeks) and LTD elimination periods (68% at 90 days) remains a critical area for plan structure optimization.