Your Complete 2026 Guide

Navigating Medicare enrollment periods can feel overwhelming, especially when terms like AEP and OEP get thrown around interchangeably. However, understanding the difference between these two critical enrollment windows is essential for ensuring you have the right Medicare coverage that meets your healthcare needs and budget. This comprehensive guide will break down everything you need to know about the Annual Enrollment Period (AEP) and the Open Enrollment Period (OEP) for 2026, helping you make informed decisions about your Medicare coverage.

What is the Annual Enrollment Period (AEP)?

The Annual Enrollment Period, commonly referred to as AEP or the Medicare Fall Open Enrollment, is the primary time each year when Medicare beneficiaries can review and make changes to their Medicare coverage. For 2026, the AEP runs from October 15 through December 7, 2025. This is your main opportunity to evaluate your current plan and make adjustments if needed.

Who Can Use AEP?

AEP is available to anyone who has Medicare Part A and/or Part B. This includes people who are currently enrolled in Original Medicare, those with Medicare Advantage plans, and those with standalone Part D prescription drug plans. Essentially, if you have Medicare, you can participate in AEP.

What Changes Can You Make During AEP?

The Annual Enrollment Period offers the most flexibility when it comes to modifying your Medicare coverage. During this time, you can:

– Switch from Original Medicare (Parts A and B) to a Medicare Advantage plan (Part C)
– Change from a Medicare Advantage plan back to Original Medicare
– Switch from one Medicare Advantage plan to another Medicare Advantage plan
– Join a standalone Part D prescription drug plan if you’re on Original Medicare
– Switch from one Part D plan to another Part D plan
– Drop your Part D coverage entirely (though this may result in late enrollment penalties if you don’t maintain creditable prescription drug coverage)
– Add or drop Medicare Advantage plans that include prescription drug coverage (MAPD)

One significant advantage of AEP is that you can make multiple changes during this period. If you enroll in a plan and later change your mind before December 7, you can switch again. Your final choice by the December 7 deadline will be the coverage that takes effect on January 1, 2026.

When Do AEP Changes Take Effect?

Any changes you make during the Annual Enrollment Period will take effect on January 1 of the following year. So changes made during the October 15 – December 7, 2025 window will begin on January 1, 2026.

What is the Open Enrollment Period (OEP)?

The term “Open Enrollment Period” can be confusing because it’s sometimes used to refer to AEP. However, there is a distinct enrollment period called the Medicare Advantage Open Enrollment Period (MA OEP), which serves a different purpose and has more limited scope than AEP.

Who Can Use the Medicare Advantage OEP?

The Medicare Advantage Open Enrollment Period is specifically designed for people who are already enrolled in a Medicare Advantage plan. If you’re on Original Medicare without a Medicare Advantage plan, you cannot use this enrollment period to join one. This is a critical distinction between AEP and OEP.

When is the Medicare Advantage OEP?

The Medicare Advantage Open Enrollment Period runs from January 1 through March 31 each year. For 2026, this means you can use the MA OEP from January 1, 2026, through March 31, 2026.

What Changes Can You Make During MA OEP?

The Medicare Advantage OEP is more restrictive than AEP in terms of what changes you can make. During this period, Medicare Advantage enrollees can:

– Switch from one Medicare Advantage plan to another Medicare Advantage plan (one time only)
– Drop their Medicare Advantage plan and return to Original Medicare
– Enroll in a standalone Part D prescription drug plan, but only if they’re dropping their Medicare Advantage plan and returning to Original Medicare

It’s important to note that you can only make one change during the MA OEP. Once you’ve switched plans or returned to Original Medicare, you cannot make another change until the next enrollment period.

When Do MA OEP Changes Take Effect?

Unlike AEP where all changes take effect on January 1, changes made during the Medicare Advantage OEP take effect on the first day of the month following your enrollment. For example, if you enroll in a new plan on February 18, your new coverage will begin on March 1.

Key Differences Between AEP and OEP

Understanding the distinctions between these two enrollment periods is crucial for making the right coverage decisions:

Timing:AEP occurs in the fall (October 15 – December 7), while MA OEP takes place in the early months of the year (January 1 – March 31).

Eligibility:AEP is available to all Medicare beneficiaries, while MA OEP is only available to those currently enrolled in a Medicare Advantage plan.

Flexibility: AEP offers much more flexibility, allowing you to make multiple changes and switch between Original Medicare and Medicare Advantage freely. MA OEP only allows one change and is limited to Medicare Advantage plan switches or returning to Original Medicare.

Scope of Changes: During AEP, you can make comprehensive changes to your Medicare Advantage, Part D, and overall Medicare structure. During MA OEP, your options are limited to Medicare Advantage plan changes only.

Effective Dates: AEP changes all take effect on January 1, while MA OEP changes take effect on the first of the month following enrollment.

Important Medicare Costs for 2026

As you evaluate your options during these enrollment periods, it’s essential to understand the costs associated with Medicare coverage in 2026. The Centers for Medicare and Medicaid Services has announced several changes to premiums and deductibles:

Medicare Part B Costs

The standard monthly premium for Medicare Part B will be $202.90 in 2026, an increase of $17.90 from the 2025 premium of $185.00. This represents approximately a 9.7% increase. The annual Part B deductible will also rise to $283, up $26 from the 2025 deductible of $257.

Higher-income beneficiaries will pay additional Income-Related Monthly Adjustment Amounts (IRMAA) based on their modified adjusted gross income from their 2024 tax returns. These surcharges can range from $284.10 to $689.90 per month for Part B, depending on income level.

Medicare Part A Costs

Most Medicare beneficiaries don’t pay a premium for Part A because they or their spouse paid Medicare taxes for at least 40 quarters. However, for those who must pay, the monthly premium will be $565 in 2026 for those with fewer than 30 quarters of coverage, or $311 for those with 30-39 quarters of coverage.

The Part A inpatient hospital deductible will increase to $1,736 in 2026, up $60 from 2025.

Medicare Part D and Prescription Drug Coverage

The average monthly premium for standalone Part D plans is projected to decrease from $38 in 2025 to $34 in 2026. However, the number of available standalone Part D plans nationwide is decreasing from 464 in 2025 to 360 in 2026.

One of the most significant changes for 2026 is the continuation of the $2,100 annual out-of-pocket cap for Part D prescription drug costs, up slightly from $2,000 in 2025. Once you reach this cap, you’ll pay nothing for covered prescription drugs for the remainder of the year. The monthly cost cap for insulin products will remain at $35 per month, and most vaccines will continue to be covered under Part D.

Medicare Advantage Plan Costs

The average monthly premium for Medicare Advantage plans with prescription drug coverage is expected to decrease from $16 in 2025 to $14 in 2026. Many Medicare Advantage plans continue to offer supplemental benefits beyond Original Medicare, including dental, vision, hearing, fitness programs, and other health-related services.

Why These Enrollment Periods Matter

Many Medicare beneficiaries make the mistake of simply auto-renewing their existing coverage without reviewing their options each year. This can be a costly mistake. Medicare plans can change their premiums, deductibles, copayments, provider networks, and prescription drug formularies annually. What worked well for you last year might not be the best option for 2026.

During AEP, you should carefully review your plan’s Annual Notice of Change, which all Medicare plans are required to send to beneficiaries by September 30. This document outlines any changes to your current plan for the upcoming year, including modifications to costs, benefits, and covered medications.

Consider whether your healthcare needs have changed over the past year. Perhaps you’ve developed new health conditions that require different specialists or medications. Maybe your current plan’s network no longer includes your preferred doctors or hospitals. Or perhaps you’ve found that you’re paying for benefits you never use, and a different plan could save you money.

What About Medicare Supplement (Medigap) Plans?

It’s important to note that neither AEP nor MA OEP provides special enrollment rights for Medicare Supplement (Medigap) plans. You can apply for a Medigap plan at any time during the year, including during AEP or MA OEP. However, unless you’re within your six-month Medigap Open Enrollment Period (which begins when you first enroll in Part B at age 65 or older) or qualify for a guaranteed issue right, Medigap insurers can use medical underwriting to determine your eligibility and premium.

As of 2026, 21 states offer at least some annual guaranteed-issue access to new Medigap plans, though in most cases this is limited to switching between Medigap plans with equal or lesser benefits. If you’re considering switching from a Medicare Advantage plan back to Original Medicare with a Medigap plan during MA OEP, be aware that you may face medical underwriting and could potentially be denied coverage based on your health history.

Special Enrollment Periods

Beyond AEP and MA OEP, there are Special Enrollment Periods (SEPs) that may allow you to make changes to your Medicare coverage outside of these standard windows. These typically occur when you experience certain qualifying life events, such as:

– Moving to a new address outside your current plan’s service area
– Losing other health insurance coverage
– Moving into or out of a long-term care facility
– Qualifying for both Medicare and Medicaid (dual eligibility)
– Moving into, living in, or moving out of a Special Needs Plan service area
– Receiving inaccurate information about whether a provider or facility is in your plan’s network

If you qualify for a Special Enrollment Period, you’ll have a limited time to make changes to your coverage based on the specific qualifying event.

Tips for Making the Most of AEP and MA OEP

Start Early:Don’t wait until the last minute. Begin reviewing your options as soon as AEP opens on October 15 to give yourself plenty of time to compare plans and make informed decisions.

Review Your Current Coverage:Carefully read your Annual Notice of Change to understand how your current plan is changing for 2026.

Assess Your Healthcare Needs: Consider any changes in your health status, medications, or preferred doctors and hospitals.

Compare Multiple Plans: Don’t just look at premiums. Compare deductibles, copayments, prescription drug coverage, provider networks, and additional benefits.

Check Prescription Drug Coverage: Use Medicare’s Plan Finder tool to ensure your medications are covered and compare costs across different plans.

Verify Provider Networks:Confirm that your doctors, specialists, and preferred hospitals are in-network for any plan you’re considering.

Consider Total Annual Costs:Look beyond monthly premiums to understand your total expected out-of-pocket costs, including deductibles, copays, and coinsurance.

Watch for Plan Changes: Some insurers are reducing their Medicare offerings or exiting certain markets for 2026. Make sure your current plan will still be available.

Get Help When Needed:Medicare can be complex. Don’t hesitate to seek assistance from qualified professionals who can help you navigate your options.

What Happens If You Miss These Enrollment Periods?

If you miss both AEP and MA OEP, you’ll generally need to keep your current Medicare coverage for another year until the next enrollment period, unless you qualify for a Special Enrollment Period. This is why it’s so important to mark these dates on your calendar and take action during the enrollment windows.

Missing the enrollment deadline can mean being stuck with a plan that no longer meets your needs, paying higher premiums than necessary, or dealing with a limited prescription drug formulary. In some cases, if you fail to maintain creditable prescription drug coverage and later decide to enroll in Part D, you may face late enrollment penalties that last for as long as you have Medicare coverage.

The Bottom Line

Understanding the difference between AEP and MA OEP is essential for managing your Medicare coverage effectively. AEP is your primary opportunity each fall to make comprehensive changes to your Medicare coverage, while MA OEP provides a second chance in early spring for those enrolled in Medicare Advantage plans to make limited adjustments.

With Medicare costs rising in 2026, including higher Part B premiums and deductibles, it’s more important than ever to carefully evaluate your options during these enrollment periods. The right plan can save you thousands of dollars annually while ensuring you have access to the healthcare services and providers you need.

Medicare planning doesn’t have to be overwhelming. With the right information and support, you can confidently navigate these enrollment periods and select coverage that provides the best value for your individual circumstances.

Get Expert Help with Your Medicare Decisions

At TrustedSRSolutions, we understand that choosing the right Medicare coverage is one of the most important financial and healthcare decisions you’ll make. Our experienced team specializes in helping individuals navigate the complexities of Medicare enrollment, comparing plans, and finding coverage that truly fits your needs and budget.

Whether you’re approaching your initial Medicare enrollment, evaluating your options during AEP, or considering a change during MA OEP, we’re here to provide personalized guidance every step of the way. We take the time to understand your unique healthcare needs, prescription requirements, preferred doctors, and financial considerations to help you make the most informed decision possible.

Don’t navigate Medicare alone. Let TrustedSRSolutions be your trusted partner in securing the healthcare coverage you deserve. Visit us at TrustedSRSolutions.com to schedule a free consultation, compare your plan options, and get answers to all your Medicare questions. Our commitment is to your peace of mind and your health. Reach out today and discover the difference that expert, personalized Medicare guidance can make.