How to Choose a Medicare Supplement Plan: What to Know 90 Days Before Turning 65

Turning 65 no longer equals full retirement age (FRA), but it is a milestone for Medicare planning.  Medicare enrollment opens three months before an individual’s 65th birthday and closes three months later (with a general enrollment period January 1 to March 31 annually).  Eligibility for a Medicare supplement plan, also known as Medigap, starts the first day of the month an individual turns 65 (must be enrolled in Medicare Part B), and lasts six months.  Medigap covers certain out-of-pocket expenses that Medicare doesn’t, but the enrollment window is critical. It is the only time guaranteed issue rights apply, meaning insurance companies cannot deny individuals coverage or charge them more based on health status.  Individuals should start preparing 90 days ahead to compare and apply for plans and sync with their Medicare coverage. Here’s a closer look at Medigap options, timelines, and tips for choosing the right coverage, with insights on how a financial advisor can guide the process.

Why 90 Days?

The three months before turning 65 allow time to explore coverage options, compare insurance quotes, and consult with a financial advisor or a State Health Insurance Assistance Program (SHIP). Most insurers can require medical underwriting after the six-month Medigap enrollment window closes, meaning they can deny coverage or raise rates based on pre-existing health conditions.

According to the Kaiser Family Foundation (KFF), applying during the open enrollment window grants access to standardized pricing and coverage without health screening.  During this period, a financial advisor can help enrollees align their healthcare coverage with their broader income and retirement strategies, such as optimizing a Health Savings Account (HSA) or managing distributions to cover premiums.

The Basics of Medigap

Private insurers sell Medigap policies to help fill the uninsured “gaps” in Medicare, such as deductibles, copayments, and coinsurance.  Most states offer 10 standardized plans (A through N).  Each lettered plan offers the same benefits regardless of insurer, but premiums, service quality, and added features can vary.

Plan G is the most comprehensive option available to new enrollees, covering nearly all out-of-pocket Medicare expenses except the Part B deductible, which is $257 in 2025.  Plans C and F, once popular, are no longer available to those newly eligible for Medicare.

Choosing Between Plan G and Plan N

At the close of 2023, approximately 5.3 million individuals were enrolled in Plan G, according to the American Health Insurance Plans (AHIP) 2024 report.  After meeting the Part B deductible, Plan G typically covers 100% of Medicare-approved services.

Plan N offers similar coverage with lower monthly premiums but includes copays for office and ER visits and does not cover excess Part B charges.  While rare, these expenses can occur if a provider does not accept Medicare assignment.

Budget and expected medical use will be major determinants in choosing between the plans. Plan G may result in better long-term value for those with frequent doctor and specialist visits.  Plan N may be more cost-effective for relatively healthy individuals comfortable with occasional out-of-pocket costs.

Pricing Models and Premium Variability

While Medigap benefits are standardized, premiums vary by insurer and pricing model.  Common pricing structures include:

• Community-rated: Everyone pays the same premium, regardless of age.
• Issue-age-rated: Premiums are based on the individual’s age at enrollment and do not increase with age.
• Attained-age-rated: Premiums increase with age.

Understanding how premiums may rise over time is central to long-term budgeting.  A 2024 NerdWallet analysis found that monthly premiums for Plan G ranged significantly by location and insurer.

State Variations You Should Know

Some states have their own rules regarding Medigap availability and protections. For example, Massachusetts, Minnesota, and Wisconsin use different plan formats from the federal model.  States like New York and Connecticut allow year-round guaranteed issue, while others restrict it to the six-month open enrollment window. These variations can significantly impact options and pricing.

A local SHIP counselor, Medicare broker, or financial advisor can help enrollees navigate state-specific regulations.

Evaluating Insurers Beyond Price

Insurance pricing matters, but so do financial strength, customer service, and added benefits. Enrollees should look for insurers with strong ratings from AM Best and the Better Business Bureau, and consider perks like household discounts, telehealth services, and wellness programs. Choosing an insurer carefully can provide cost control, a smoother claims process, and ongoing support throughout retirement.

Medicare and Medigap decisions are a vital part of your retirement plan.  The 90-day period preceding your 65th birthday is a time for critical planning and informed decision-making to secure coverage that will serve you for life.  At SHP Financial, we help clients integrate income and healthcare planning to complement each other.  Our team can guide you through the Medigap selection process to cover your medical needs and support your financial goals. 

Schedule your complimentary consultation today, so that your 65th year begins with confidence, clarity, and coverage.