← Back to BlogMedicare Supplement

Medicare Supplement Plans: Your Complete Medigap Guide

By New Jersey Medicare Advisory • April 29, 2026

Medicare Supplement Plans: Your Complete Medigap Guide

If you're enrolled in Original Medicare (Parts A and B), you've probably noticed that it doesn't cover everything. Deductibles, coinsurance, and copayments can add up quickly. That's where Medicare Supplement Insurance, commonly called Medigap, comes in. These policies are designed to help fill the "gaps" in Original Medicare coverage, giving you more predictable healthcare costs and greater peace of mind.

What Is Medigap and How Does It Work?

Medigap policies are sold by private insurance companies but are standardized by federal and state law. This means that a Plan G from one company offers the same basic benefits as Plan G from another company—though the premiums may differ.

Here's how Medigap works alongside Original Medicare: When you receive healthcare services, Original Medicare pays its share first. Then your Medigap policy pays its share according to your plan's benefits. You'll typically pay a monthly premium for your Medigap policy in addition to your Medicare Part B premium. Most Medigap policies don't include prescription drug coverage, so you'll likely want to enroll in a separate Medicare Part D plan.

It's important to note that Medigap only works with Original Medicare. If you join a Medicare Advantage Plan (Part C), you cannot use a Medigap policy, and it's actually illegal for an insurance company to sell you one if they know you're in a Medicare Advantage Plan.

Understanding the Standardized Plan Letters

Medigap policies are identified by letters: A, B, C, D, F, G, K, L, M, and N. Each letter represents a different set of standardized benefits. In New Jersey and most states, these plans are standardized, making it easier to compare coverage options.

Some plans offer more comprehensive coverage than others. For example, Plans F and G are among the most comprehensive, covering most out-of-pocket costs. However, Plan F is only available to those who became eligible for Medicare before January 1, 2020. For those newly eligible, Plan G has become a popular choice as it offers similar comprehensive coverage.

Plans K and L require you to pay a percentage of costs, but they also have an out-of-pocket limit. Once you reach that limit, the plan pays 100% of covered services for the rest of the calendar year. Plans M and N offer moderate coverage with some cost-sharing, which typically results in lower monthly premiums.

Plan N, for instance, requires small copayments for some doctor visits and emergency room visits that don't result in admission. This cost-sharing helps keep premiums lower while still providing substantial coverage.

Monthly Premiums and Pricing Considerations

Medigap premiums can vary significantly between insurance companies, even for the same plan letter. Insurance companies may use different pricing methods:

Community-rated (no-age-rated): Everyone pays the same premium regardless of age.

Issue-age-rated: Your premium is based on your age when you buy the policy and typically doesn't increase due to age.

Attained-age-rated: Premiums increase as you get older.

Your premium may also vary based on factors like your location, tobacco use, and gender (where state law allows). This is why it's crucial to compare plans from multiple carriers. The same coverage can cost significantly different amounts depending on the insurance company.

Guaranteed Issue Rights and Enrollment Timing

The best time to buy a Medigap policy is during your Medigap Open Enrollment Period. This six-month period begins when you're 65 or older and enrolled in Medicare Part B. During this time, you have guaranteed issue rights—insurance companies cannot deny you coverage or charge you more due to pre-existing health conditions.

There are also certain situations that trigger guaranteed issue rights outside this initial period, such as when you lose employer coverage or if your Medicare Advantage plan leaves your area.

Outside of guaranteed issue periods, insurance companies in most states can use medical underwriting, potentially denying coverage or charging higher premiums based on your health status.

Making the Right Choice for Your Needs

Choosing the right Medigap plan depends on your individual circumstances, including your health status, budget, and how often you visit doctors or need medical services. Consider factors like:

  • How much coverage you want versus what premium you're comfortable paying
  • Whether you travel frequently (some plans offer foreign travel emergency coverage)
  • Your current health and anticipated medical needs
  • Whether you see specialists regularly

Working with a licensed Medicare advisor can help you navigate these options and find a plan that fits your specific situation.

Get Expert Help Choosing Your Medigap Plan

Selecting the right Medicare Supplement plan is an important decision that affects both your healthcare coverage and your budget. The team at New Jersey Medicare Advisory is here to help you understand your options and find the plan that best meets your needs.

Call us today at 856-221-7051 to speak with a licensed Medicare advisor who can answer your questions and guide you through the Medigap selection process. Our personalized service ensures you make an informed decision about your Medicare coverage.