Plan G is a standardized supplement that covers most of what Medicare Part A and Part B don't

Medicare Supplement Plan G is one of ten standardized plans sold by private insurance companies. It pays for costs that Original Medicare leaves you responsible for — copayments, coinsurance, and deductibles. Plan G covers nearly everything except the Part B deductible (which you pay once per year) and routine dental, vision, and hearing care, which no supplement covers.

The word "standardized" matters: every Plan G sold by every insurer covers the same benefits. The only difference between companies is price and customer service. This means you can compare quotes from multiple insurers knowing you are comparing the same thing.

Plan G became the most popular supplement in 2020 when Medicare rules changed. Before that, Plan F covered the Part B deductible too. Now that Plan F is closed to new enrollees, Plan G is where most people land.

Key Takeaways

  • Plan G covers copayments, coinsurance, and most deductibles that Original Medicare requires you to pay out of pocket.
  • You still pay the Part B deductible ($240 in 2024, though this amount changes yearly) before Plan G coverage begins.
  • Plan G works only with Original Medicare — not with Medicare Advantage or Medicare Part D prescription drug plans.
  • Premiums vary by insurer and your age, so comparing quotes from at least three companies usually saves money.
  • You can switch to a different supplement plan during your open enrollment period without medical underwriting.

What Plan G actually pays for

Plan G covers the Part A deductible (the amount you owe for a hospital stay), which is $1,676 per benefit period in 2024. It also covers Part A coinsurance — the daily cost-sharing amounts for hospital stays beyond 60 days. If you need skilled nursing facility care, Plan G covers the coinsurance after day 20.

For Part B (doctor visits and outpatient care), Plan G covers the 20% coinsurance you would normally owe after you meet the deductible. It also covers the cost of a second opinion before surgery and covers excess charges if your doctor does not accept Medicare assignment — though this is rare.

Plan G also covers Part B excess charges, which occur when a doctor charges more than Medicare allows. In states where this is permitted, a doctor can bill you for the difference. Plan G pays that difference, so you never see the bill.

One thing Plan G does not cover: the Part B deductible itself, which you pay once per calendar year before any coinsurance kicks in. In 2024 this is $240. You also pay for anything Medicare does not cover at all — dental work, eyeglasses, hearing aids, and long-term care.

How Plan G premiums work and what they depend on

You pay a monthly premium to the insurance company that sells you Plan G. This premium is separate from your Medicare Part B premium, which you pay to Medicare. The Plan G premium varies based on three main factors: the insurance company, your age, and your state.

Most insurers use one of two pricing methods. Attained-age pricing means your premium goes up as you get older. Issue-age pricing means your premium is locked to your age when you first buy the plan, then rises only with inflation and company-wide rate changes. Issue-age pricing usually costs more upfront but may cost less over time if you live into your 80s.

In 2024, Plan G premiums range from roughly $100 to $300 per month depending on where you live and which company you choose. Some states regulate how much insurers can raise premiums year to year; others do not. Calling three or four insurers for quotes takes 20 minutes and often saves $50 to $100 per month.

When you can enroll in Plan G and when you cannot

The best time to buy Plan G is during your Medigap open enrollment period, which lasts six months starting the month you turn 65 and enroll in Medicare Part B. During this window, insurers cannot deny you coverage or charge you more based on health conditions — a protection called may provide issue.

If you miss this window, you can still buy Plan G, but insurers may refuse to sell it to you or charge you more if you have diabetes, heart disease, or other chronic conditions. Some states have additional open enrollment periods, usually 30 to 60 days long, but these vary by location and insurer.

You can switch from one Plan G to another Plan G at any time without underwriting, as long as you are switching between insurers. You can also switch to a different supplement plan (Plan N, Plan D, etc.) during your annual open enrollment period in the fall, though switching away from Plan G usually means paying more out of pocket for medical care.

Plan G versus Plan N and other alternatives

Plan N is cheaper than Plan G but leaves you responsible for more costs. With Plan N, you pay a copayment for doctor visits ($20) and emergency room visits ($250, waived if admitted), and you pay the Part B excess charges if they occur. Most people choose Plan G because the lower out-of-pocket costs are worth the higher premium.

Plan F is similar to Plan G but also covers the Part B deductible. However, Plan F is closed to anyone who did not have Medicare before January 1, 2020. If you are new to Medicare now, Plan F is not an option.

Some people choose Medicare Advantage instead of Original Medicare plus a supplement. Medicare Advantage plans have lower premiums but require you to use in-network doctors and have annual out-of-pocket limits. They work differently from supplements and are not a direct comparison.

Common mistakes people make with Plan G

The most common mistake is assuming Plan G covers everything. It does not cover the Part B deductible, dental, vision, hearing, or long-term care. Some people also assume they can use Plan G with Medicare Advantage — you cannot. Supplements work only with Original Medicare.

Another mistake is not comparing prices. Many people buy Plan G from the first company they call or from the company that mailed them a brochure. Calling three insurers usually reveals price differences of $30 to $60 per month, which adds up to $360 to $720 per year.

A third mistake is waiting to enroll. If you delay past your six-month open enrollment window, you may face medical underwriting, which can mean higher premiums or outright denial. If you are turning 65 soon, contact insurers now for quotes, even if you do not enroll when ready.

How to compare Plan G quotes from different insurers

Start by listing the major insurers in your state. The largest sellers of Plan G nationally include AARP/UnitedHealthcare, Humana, Cigna, Anthem, and regional carriers. Your state insurance commissioner's office publishes a list of licensed insurers selling supplements in your state.

Call each insurer and ask for a quote for Plan G at your age and in your zip code. Write down the monthly premium, whether it uses attained-age or issue-age pricing, and what the premium was last year (to see the rate of increase). Ask whether the company offers any discounts — some offer small reductions for paying by automatic bank draft or for being a long-time customer.

Once you have three or four quotes, compare the premiums and the pricing method. Do not choose based on brand name alone. A smaller regional insurer may offer better pricing than a national name. After you choose, you can enroll by phone, mail, or online depending on the company.

Frequently Asked Questions

Do I have to buy Plan G, or can I skip the supplement and just use Original Medicare?

You can skip the supplement. You will pay less in premiums but more out of pocket when you see doctors or need hospital care. Most people find that the supplement premium saves money over time because it eliminates the 20% coinsurance on doctor visits and covers hospital deductibles.

Can I use Plan G with a Medicare Advantage plan?

No. Supplements like Plan G work only with Original Medicare. If you have a Medicare Advantage plan, you cannot buy a supplement. If you want to switch from Advantage to Original Medicare plus a supplement, you can do so during the annual open enrollment period in the fall.

What happens to my Plan G if I move to a different state?

Your coverage continues, but your premium may change because rates vary by state. Contact your insurer to find out whether your rate will change and by how much. You can also shop for a new Plan G in your new state during your annual open enrollment period.

Does Plan G cover prescription drugs?

No. You need a separate Medicare Part D prescription drug plan, which you buy from a different insurance company. You can enroll in Part D when you first turn 65 or during the annual open enrollment period in the fall.

Can an insurer refuse to sell me Plan G because of my health?

Only if you are outside your open enrollment period. During your six-month Medigap open enrollment window after turning 65, insurers must sell you Plan G regardless of health. After that window closes, they can deny you or charge more. Some states have additional may provide-issue periods, so check your state's rules.