What dates are Medicare Annual Enrollment and what can I change?

Quick Answer

Medicare's Annual Enrollment Period runs October 15 through December 7 each year. During this time you can switch Medicare Advantage plans, move from Original Medicare to Medicare Advantage or back, and change your Part D drug plan.

Detailed Explanation

Every year from October 15 to December 7, Medicare opens a window where you can make changes to your coverage. Whatever you choose takes effect January 1 of the following year. This is the main time most people review and update their plans. During Annual Enrollment you can switch from one Medicare Advantage plan to another, drop Medicare Advantage and return to Original Medicare, or add and change a standalone Part D prescription drug plan. If you are on Original Medicare with a standalone drug plan, you can swap to a different drug plan or drop it entirely, though dropping without other creditable coverage could mean a penalty later. There is also a separate window called the Medicare Advantage Open Enrollment Period, which runs January 1 through March 31. During that window, people already enrolled in a Medicare Advantage plan can switch to a different Advantage plan or move back to Original Medicare. You cannot, however, use that January window to enroll in Medicare Advantage for the first time if you are currently on Original Medicare. Plan details, premiums, drug formularies, and networks can all change from year to year, so reviewing your Annual Notice of Change, the letter your plan sends each fall, before making any decision is a smart starting point.

How This Applies in Utah

In Utah, plan availability varies by county. Rural areas like Garfield, Kane, and Daggett counties may have only one or two Medicare Advantage options, while the Wasatch Front typically has more carriers to compare, including SelectHealth, Regence BlueCross, UHC, Humana, Aetna, and others.

What This Means For You

For you, this means October 15 is the date to put on your calendar each year to review whether your current plan still fits your needs and budget.

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.