Medicare Advantage 2027 Open Enrollment: 8 Steps to Choose the Best Plan

The Medicare Advantage 2027 open enrollment period runs from October 15 through December 7, 2026—and the plan you choose (or fail to switch) determines your out-of-pocket healthcare costs, provider access, and drug coverage for all of 2027. With more than 4,000 Medicare Advantage plans nationally and significant changes taking effect in 2027 under new CMS regulations, this is the year to conduct a careful comparison rather than simply renewing your current plan. Here is the 8-step expert guide to making the right decision.

Table of Contents

• Key 2027 Open Enrollment Dates
• Major Medicare Advantage Changes for 2027
• 8 Steps to Choose Your Best Plan
• Medicare Advantage vs. Original Medicare: When Each Makes Sense
• Types of Medicare Advantage Plans
• How to Use Star Ratings
• How and Where to Enroll
• Frequently Asked Questions

Key Medicare Advantage 2027 Enrollment Dates

The October 15–December 7 Annual Enrollment Period is your primary opportunity to switch plans with 2027 coverage beginning January 1. This window applies whether you are currently on Original Medicare, a Medicare Advantage plan, or a standalone Part D prescription drug plan. Coverage changes made during AEP become effective January 1, 2027.

Major Medicare Advantage Changes Taking Effect in 2027

CMS has implemented several significant regulatory changes that will reshape Medicare Advantage plans beginning in 2027. Understanding these shifts is essential before you select a plan:

Behavioral Health Cost-Sharing Parity

Starting January 1, 2027, Medicare Advantage plans are required to match or improve upon Original Medicare cost-sharing for all mental health and substance use disorder services. This means you cannot be charged higher copays for psychiatry, psychology, or addiction treatment visits under a 2027 MA plan than you would pay under Original Medicare Parts A and B. Seniors on MA plans that previously had high behavioral health copays will see meaningful savings under this rule.

Prior Authorization Reforms

CMS’s 2026 final rule—effective June 1, 2026—mandates that MA plans approve urgent prior authorization requests within 72 hours, standard requests within 7 days, and that all denials include a written clinical rationale. All PA denial reviews must be conducted by a physician or clinical peer. For 2027 plans, these protections carry forward with stronger enforcement, reducing the risk of inappropriate claim denials that have been a major concern with MA plans in recent years.

CMS Marketing Crackdown

The April 2026 CMS Final Rule significantly tightened rules on MA plan marketing, including prohibitions on misleading television advertisements that promise benefits not universally available, restrictions on “scope of appointment” violations at sales events, and new penalties for agents who enroll beneficiaries in plans without consent. When comparing plans for 2027, be skeptical of any advertisement claiming zero-premium plans with extensive extras—verify actual benefits on Medicare.gov before enrolling.

Star Ratings Accountability

CMS is tightening Star Rating methodology for 2027 to reduce “gaming” of quality metrics. Plans scoring below 3 stars for three consecutive years face enrollment freezes. This means some currently available plans may lose enrollment eligibility for 2027—another reason to verify your current plan’s Star Rating before the AEP deadline.

8 Steps to Choose Your Best Medicare Advantage Plan for 2027

Step 1: Read Your Annual Notice of Change (ANOC)

Your current plan must mail your ANOC by September 30, 2026. This document details every change to your plan for 2027: premium changes, deductible changes, copay/coinsurance adjustments, formulary (drug list) changes, and provider network modifications. Read it carefully—a plan that looks good on paper in 2026 may have cut benefits significantly for 2027. If your ANOC shows your premium increased by more than $30/month, a key drug moved to a higher tier, or a specialist you use left the network, it is a strong signal to shop alternatives.

Step 2: List Your Current Doctors and Facilities

Write down the full names and practice affiliations of every healthcare provider you use: primary care physician, specialists (cardiologist, rheumatologist, endocrinologist, etc.), hospital, urgent care, outpatient surgery center, and any skilled nursing facility you might need. Network restrictions are the #1 reason seniors regret their MA plan choice. HMO plans require in-network providers and referrals; PPO plans allow out-of-network care at higher cost. A specialist you see monthly for a chronic condition must be in-network for your coverage to function as advertised.

Step 3: Verify Provider Networks for Each Plan

Use the plan’s online provider directory (linked from Medicare.gov) to confirm each of your providers is currently in-network. Do not rely on last year’s directory—networks change annually. Call the provider’s office directly to confirm they accept the specific plan, since directories are not always updated in real time. Out-of-network care under an HMO may result in no coverage at all, potentially leaving you with a bill for the full Medicare-approved amount.

Step 4: Check Your Drug Formulary

Export your complete medication list from your pharmacy and use the Medicare Plan Finder at Medicare.gov/plan-compare to enter every drug, dose, and pharmacy. The tool calculates your estimated annual drug costs across all available plans—this is the most critical step for seniors on multiple brand-name medications. Under the 2026 Part D $2,100 OOP cap (carrying into 2027 plans), high-cost drugs become more manageable, but formulary tier placement still dramatically affects copays before the cap is reached. A drug on Tier 5 (specialty) with a 25-33% coinsurance hits the cap much faster than the same drug on Tier 3.

Step 5: Evaluate Extra Benefits Carefully

In 2026, 97% of MA plans include some dental, vision, and hearing benefits—but the scope varies enormously. A plan advertising “dental coverage” may only cover cleanings and X-rays, not crowns or implants. Evaluate: Does the dental benefit cover restorative work (crowns, dentures, partials)? What is the annual dental allowance ($1,000? $2,500? $5,000)? Does the vision benefit cover both frames and contacts? Is the hearing aid allowance sufficient for the devices you need ($500 per ear vs $2,500 per ear makes a major difference)? Additional extras like OTC allowances ($50–$150/quarter for vitamins, bandages, etc.), transportation to medical appointments, and home-delivered meals after hospitalization should be factored into total plan value.

Step 6: Compare Total Annual Costs — Not Just Premium

The average MA plan premium is approximately $14/month in 2026, but premium is the least important number in your cost analysis. Focus on: annual deductible (many MA plans have $0 deductible for medical services), primary care copay ($0–$25/visit), specialist copay ($25–$50/visit), inpatient hospital cost-sharing (day 1-7 copay, which can be $250-$500/day under some MA plans), and—critically—the annual out-of-pocket maximum. The 2026 federal OOP maximum for MA is $9,350 for in-network and $14,000 for combined in-and-out-of-network. A plan with a $3,500 OOP maximum at $65/month premium may cost you less in a bad health year than a $0-premium plan with an $8,000 OOP maximum.

Step 7: Check Star Ratings

CMS assigns every MA plan 1-5 stars annually based on quality metrics: preventive care delivery, management of chronic conditions, member satisfaction, customer service responsiveness, and appeals handling. Use Medicare.gov/plan-compare to filter plans by Star Rating. Aim for plans rated 4-5 stars; plans rated 1-2 stars have documented quality problems. 5-star plans receive a special enrollment period open year-round—if a 5-star plan is available in your area, you can switch to it at any time outside AEP. Plans with 5-star ratings have also been shown in multiple CMS analyses to achieve better health outcomes for their members.

Step 8: Enroll Through a Trusted Channel

You can enroll through Medicare.gov/plan-compare (the official tool), by calling 1-800-MEDICARE (1-800-633-4227), through a licensed insurance agent or broker (they are paid by the plan—not by you), or through a SHIP (State Health Insurance Assistance Program) counselor who provides free, unbiased guidance. Never pay for enrollment assistance; it is always free. SHIP counselors are trained volunteers who have no financial incentive to push any specific plan. Find your local SHIP at shiphelp.org.

Medicare Advantage vs. Original Medicare: When Each Makes Sense

Critical warning: If you switch from Medicare Advantage to Original Medicare outside your initial 6-month Medigap open enrollment window, you may be subject to medical underwriting for Medigap policies. In most states (not California, Connecticut, Massachusetts, or New York), insurance companies can deny you Medigap coverage or charge higher premiums based on pre-existing conditions. Once you develop chronic conditions, returning to Original Medicare + Medigap may become prohibitively expensive or impossible without a guaranteed-issue right.

Types of Medicare Advantage Plans Explained

Not all Medicare Advantage plans work the same way. The four main plan types differ significantly in provider flexibility and cost structure: HMO (Health Maintenance Organization) plans require you to use in-network providers and get referrals from your PCP for specialist visits—lowest premium, least flexibility. PPO (Preferred Provider Organization) plans allow out-of-network care at higher cost-sharing and do not require referrals—better flexibility, higher premium. PFFS (Private Fee-for-Service) plans set their own payment terms; any provider who accepts those terms can see you—less common and less predictable. SNPs (Special Needs Plans) are designed for beneficiaries who are dual-eligible (Medicare + Medicaid), institutionalized, or have specific chronic conditions (D-SNP, I-SNP, C-SNP)—often the best option for seniors with complex needs who also qualify for Medicaid.

How Star Ratings Work and Why They Matter

CMS calculates Star Ratings using dozens of quality measures grouped into five domains: Staying Healthy (screenings and vaccinations); Managing Chronic Conditions (diabetes, hypertension, cardiovascular disease); Member Experience with the Health Plan; Member Complaints and Changes in the Health Plan’s Performance; and Health Plan Customer Service. Plans are rated annually; the 2027 Star Ratings will be released in fall 2026 and will be visible on Medicare.gov before the October 15 AEP start date. Plans with 4+ stars bonus: CMS pays them an enhanced premium rebate which plans can use to offer richer supplemental benefits. A 5-star plan available in your zip code is worth serious consideration even if the premium appears slightly higher.

How to Enroll in Medicare Advantage for 2027

The simplest enrollment method is Medicare.gov/plan-compare—enter your zip code, list your drugs and dosage, and the tool calculates your estimated total annual cost across all available plans. You can enroll directly through the site, which instantly sends your enrollment to CMS. Alternatively, calling 1-800-MEDICARE (available 24/7) connects you with a CMS representative who can process enrollment over the phone. For personalized guidance with no sales pressure, contact your SHIP counselor (shiphelp.org) who will help you compare plans without steering you toward commission-driven options. If working with a private insurance broker, confirm they are comparing all available plans rather than only those they represent.

Frequently Asked Questions

Can I switch from Medicare Advantage back to Original Medicare during open enrollment?

Yes—you can switch from any Medicare Advantage plan back to Original Medicare during the AEP (October 15–December 7) each year, with coverage reverting January 1. You will need to separately enroll in a standalone Part D prescription drug plan to maintain drug coverage. The critical caveat: without a Medigap policy, you will face Original Medicare’s 20% coinsurance with no annual OOP maximum. In most states, if you missed your initial 6-month Medigap guaranteed-issue period at age 65, insurers can now deny coverage or charge higher rates based on your health history. Carefully evaluate this risk before switching, especially if you have developed chronic conditions since first enrolling in Medicare.

What is the difference between Medicare Advantage and Medicare Supplement (Medigap)?

These are two entirely different ways to get Medicare coverage. Medicare Advantage (Part C) is an alternative to Original Medicare—a private insurance plan that replaces Parts A and B and usually includes Part D. You use the plan’s network of providers. Medigap (Medicare Supplement) works alongside Original Medicare—it pays the gaps in coverage (20% coinsurance, deductibles) that Original Medicare leaves behind. You keep your Original Medicare card and see any Medicare-accepting provider nationally; Medigap pays your share. You cannot have both Medicare Advantage and a Medigap policy simultaneously—they are mutually exclusive coverage structures.

Are Medicare Advantage plans safe for seniors with serious illnesses?

This depends heavily on the specific plan and your condition. For seniors with complex medical needs requiring frequent specialist visits, hospital admissions, or treatments at specific cancer centers or academic medical centers, Original Medicare with Medigap Plan G is typically more protective—any Medicare-accepting provider nationwide, no referrals, and effectively no OOP with Plan G. For seniors who are healthy or whose care is entirely within a local provider network, a high-quality (4-5 star) MA plan can provide excellent care at significantly lower monthly cost. The 2027 prior authorization reforms reduce—but do not eliminate—the risk of treatment denials under MA plans for complex conditions.

Related Articles You May Find Helpful

• Medicare 2026: The Complete Guide for Seniors
• Medicare Plan G 2027: Real Premium Rates, What’s Covered & Best States to Buy
• Medicare Savings Program 2027: 4 Plans That Can Eliminate Your Premiums
• How to Enroll in Medicare at 65 in 2026: 7-Step First-Timer’s Guide
• Medicare Part B Late Enrollment Penalty 2026: Avoid Costly Mistakes

Sources

• Medicare.gov Plan Compare Tool
• CMS: Contract Year 2027 Policy Changes for Medicare Advantage
• SHIP Help: Free Medicare Counseling Nationwide