What is the Annual Enrollment Period for Medicare?

Quick Answer

The Annual Enrollment Period, or AEP, runs from October 15 to December 7 each year. It's the main window when Medicare beneficiaries can switch, join, or drop Medicare Advantage or Part D drug plans.

Detailed Explanation

The Annual Enrollment Period is the one time each year when most Medicare beneficiaries can make changes to their drug coverage or Medicare Advantage coverage without needing a special qualifying reason. It runs the same dates every year: October 15 through December 7. Any changes you make take effect January 1 of the following year.During AEP, you can switch from one Medicare Advantage plan to another, drop Medicare Advantage and return to Original Medicare, join or switch a standalone Part D drug plan, or add a Part D plan if you didn't have one before (though a late enrollment penalty may apply if you went without creditable drug coverage for a while).This is also the period when it pays to actually compare plans rather than just staying put. Plans change their premiums, their drug formularies (approved drug lists), their networks of doctors, and their extra benefits every year. A plan that worked well for you last year might not be the right fit going forward.AEP gets a lot of TV and mail advertising, and it can feel overwhelming. The key is to focus on what matters for your specific situation: which doctors you want to keep, which medications you take, and how much you can reasonably spend out of pocket. A licensed local agent can do a side-by-side comparison without charging you for the help.

How This Applies in Utah

Utah beneficiaries have access to carriers like SelectHealth, Regence BlueCross, UHC, Humana, Aetna, Molina, Devoted Health, Cigna, and Wellcare, though plan availability varies by county. Those in rural areas like Garfield, Kane, or Daggett counties typically have fewer Medicare Advantage options. Utah's ADRC offices offer free, unbiased counseling during AEP if you want help comparing plans.

What This Means For You

For you, this means October 15 through December 7 is when you should review your current coverage, compare available plans, and make any changes before the new year begins.

Disclaimer

How Resting Sycamore Advisors Uses CMS Data

Our Commitment to Reliable Medicare Information

At Resting Sycamore Advisors, we work to provide accurate, current, and trustworthy information about Medicare Advantage, Medicare Part D, and Special Needs Plans.

To do that, we use data published by the Centers for Medicare & Medicaid Services (CMS), which is the official source for Medicare plan and enrollment information.

CMS Data Sources We Rely On

Our Medicare plan pages and comparison tools are powered by CMS datasets, including:

  • Medicare Advantage and Part D Landscape Files for annual plan availability and benefit details
  • Plan Benefits Package (PBP) Files for detailed benefit and coverage information
  • Part C and Part D Performance Data for quality ratings and plan performance measures
  • Monthly Enrollment Data for enrollment counts by contract, plan, state, and county

When possible, we link to the original CMS resources so you can review the source material directly.

How Often We Update Our Data

We follow the CMS release schedule and update our website as new data becomes available.

Annual Plan Year Updates (September)

We load new plan year Landscape and PBP files before the Medicare Annual Enrollment Period (October 15 through December 7). We also monitor CMS.gov for updates or revisions and refresh our content when needed.

Mid-Year Updates

We update enrollment and performance data as CMS publishes revised files, which are typically released monthly or quarterly.

Ongoing Maintenance

We routinely monitor CMS announcements for corrections, reissued files, or other changes and update our pages accordingly.

Each plan page includes a Last Accessed date so visitors can see when the source information was most recently reviewed.

How We Prepare CMS Data for Our Website

CMS data can be difficult to read in raw form. To make it easier to use, we format and organize the data for clarity.

This includes:

  • Standardizing plan identifiers such as contract ID, plan ID, and segment
  • Normalizing terminology so common Medicare terms are presented consistently
  • Organizing plan information by state, county, and ZIP code to match how people shop for coverage

All data values come from CMS. We do not change the underlying values beyond formatting, organization, and presentation.

Version Tracking and Transparency

We keep internal records of the CMS dataset versions used on our site.

Major Version History

  • Current Version: CY2025 Medicare Advantage and Part D Landscape Files (v1.0, published October 2025)
  • Prior Version: None. Resting Sycamore Advisors first began publishing structured Medicare plan information in March 2025

If CMS issues corrected or revised files, we update our website to reflect the latest available version.

Important Limitations

Please keep the following in mind:

  • CMS is the official source of truth. For enrollment and coverage decisions, always confirm details with Medicare.gov or 1-800-MEDICARE.
  • Data timing can vary. Enrollment and performance updates may appear on our website a few weeks after CMS publishes changes.
  • Plan details can change. Plan availability, costs, and benefits may change. Always verify current details directly with the plan provider.

Need Help From Official Medicare Resources?

For personalized Medicare assistance, please use these official resources:

  • Medicare.gov Help Center — https://www.medicare.gov
  • 1-800-MEDICARE (1-800-633-4227) TTY: 1-877-486-2048
  • State Health Insurance Assistance Program (SHIP) — free local counseling for Medicare beneficiariesIf you want, I can also give you a shorter legal-style version for a footer or /disclaimer page summary.