Seven Costly Medicare Annual Enrollment Mistakes to Avoid

The Medicare Annual Enrollment Period (AEP) runs from October 15 to December 7 each year. During this window, beneficiaries can review, drop, or switch their Medicare plans. 

SelectQuote’s licensed insurance agents speak with thousands of Medicare beneficiaries every year during AEP. We see firsthand where people get confused, which options get overlooked, and how small assumptions can end up costing you money. To help you protect both your health coverage and your wallet, we’ve compiled some of the most common AEP mistakes and how you can avoid them this year.

 1. Ignoring Your Medicare Annual Notice of Change

Every September, your insurance carrier sends an Annual Notice of Change (ANOC) detailing all modifications to your coverage taking effect on January 1. Many beneficiaries set this document aside without reading it, especially if they’re satisfied with their current care. However, plans change every year, and failing to review your ANOC may mean encountering surprise medical bills or coverage gaps in the new year.

SelectQuote Agent Insight:

Our agents frequently get calls in January from concerned beneficiaries whose plan had a $0 premium the year before. They assumed nothing had changed, only to discover at the pharmacy counter that their routine medication was moved to a higher copay tier or removed from the formulary entirely. Taking a few minutes to review your ANOC in October prevents costly surprises in January.

Your ANOC Review Checklist

Use this checklist to evaluate your notice during the 2026 AEP season to ensure your plan continues to fit your health needs and budget for 2027.

• Premium and Deductible Changes: Check whether your monthly plan premium, annual medical deductible, or prescription deductible will increase for 2027.

• Formulary and Tier Adjustments: Review the plan’s drug list (formulary) to confirm your regular medications are still covered, haven't moved to a more expensive pricing tier, and haven't added new prior authorization or step therapy rules.

• Part D Out-of-Pocket Cap Adjustment: Verify how your notice reflects the updated Part D out-of-pocket spending limit—projected to adjust from $2,100 in 2026 to $2,400 in 2027 per CMS releases—so you can budget accurately for catastrophic coverage thresholds.

• Provider Network Lean-Outs: Cross-reference your doctors, specialists, local hospitals, and preferred retail pharmacies against the updated 2027 network directory to ensure they remain in-network.

2. Not Realizing Your Plan is Leaving Your Area

Millions of beneficiaries were affected by plan terminations in 2025. Market shifts like this happen every year. Failing to verify whether your plan is still available could leave you without coverage or auto-enrolled in a plan that doesn’t meet your needs.

3. Not Checking the Updated Part D Spending Cap

The structure of Medicare Part D prescription drug coverage has undergone significant changes under the Inflation Reduction Act. Historically, beneficiaries faced complex phases, including the initial coverage limit, the coverage gap (or "donut hole"), and catastrophic coverage, which still required a 5% coinsurance payment.

The elimination of catastrophic coinsurance in 2024 paved the way for an established limit on annual prescription costs. For 2026, out-of-pocket spending on covered Part D medications is capped at $2,100. Once you hit that limit, you pay $0 for your covered drugs for the remainder of the calendar year.

However, assuming this cap remains identical year after year is a common oversight when budgeting for healthcare.

SelectQuote Agent Insight:

While the Part D spending cap for 2026 sits at $2,100, the CMS 2027 Rate Announcement projects the out-of-pocket maximum will increase to $2,400 in 2027 as indexation kicks in. Because this limit adjusts with national health spending growth, relying solely on last year's numbers can throw off your fixed-income budget. A SelectQuote licensed insurance agent can help keep you informed about changes to plan costs and formularies so you won’t be caught off guard.

4. Assuming Your Doctor is Still In Network

Some Medicare Advantage plans work exclusively with local networks. Networks can change, so if staying with a specific doctor is important to you, confirm they remain in the network each year. Even if you aren’t tied to a specific provider, reviewing your plan annually ensures you’re getting the most affordable coverage. If you remain in a plan after your doctor leaves its network, you could face significantly higher out-of-network rates or have to cover the full cost of your visits out of pocket.

SelectQuote Agent Insight:

Unexpected network adjustments—especially specialists leaving Health Maintenance Organization (HMO) networks—are one of the top reasons beneficiaries call SelectQuote to change plans during enrollment season. Many people don't realize their preferred doctor is no longer covered until they try to book an appointment in January. Before enrolling you in any plan, SelectQuote’s licensed insurance agents cross-reference your primary care doctors, specialists, and preferred hospitals directly inside carrier system directories to verify they remain in-network. 

5. Mixing Up Medicare Advantage Plans vs. Medicare Supplement Plans

Medicare Advantage plans and Medicare Supplement Insurance plans (also known as Medigap) have different rules and protections. If you stay in a Medicare Advantage plan that doesn't fit your needs past your initial trial period, you lose your guaranteed issue rights. This could prevent switching to a Medigap plan later. Knowing the differences before enrollment is critical in 2026. 

6. Signing Up for the Same Medicare Plan as Your Friends or Spouse

Friends and family are great references, but your personal health needs are unique. Medication usage, preferred pharmacies, and doctor visits all affect your total healthcare costs. Choosing a plan solely based on others’ experiences could lead to overspending or coverage gaps. Comparing multiple options will help you find the right plan for your situation. 

7. Not Being Aware of Medicare Scammers

During the Annual Enrollment Period (AEP), beneficiaries see an increase in targeted marketing materials, television advertisements, phone calls, and mailers. While many of these communications are legitimate marketing efforts from Medicare-approved plans, it is essential to distinguish between standard advertising, misleading marketing, and outright fraudulent attempts to obtain your personal information. Remember: official government representatives from Medicare or Social Security will never call you uninvited to sell a plan or ask for personal financial information.

SelectQuote Agent Insight:

During AEP, beneficiaries often tell us they feel completely overwhelmed by the rise in TV ads and conflicting mailers. Rather than navigating confusing sales pitches alone, working with an independent advocate like SelectQuote gives you clarity. In one straightforward phone call, our licensed insurance agents can compare your plan options across a variety of highly recognized national carriers. We objectively evaluate your doctors, prescriptions, and budget without high-pressure sales tactics—helping you make an informed decision with confidence and peace of mind.

Let Us Help You Navigate the Complexities of Medicare Plans

Medicare enrollment can seem overwhelming, but SelectQuote can help. Our licensed insurance agents will get to know your needs and then independently shop Medicare Supplement insurance plans and Medicare Advantage plans on your behalf. The service is free, and there’s no obligation to enroll.