Medicare by State: How Medicare Advantage, Medigap and Part D Vary

Original Medicare — Medicare Part A and Part B — is a federal program. You can use it anywhere in the United States if you are traveling or move to another state.

But states may make their own Medicare rules — as long as they meet basic Medicare requirements.

In addition, Medicare Advantage, Medigap and Medicare Part D prescription drug plans are sold by private insurers. The insurers are regulated by the state where they are located. This means the rules for these plans vary from state to state.

If you move to another state — or even a different part of your state — you may have to replace your Medicare Advantage, Medigap or Part D plan.

Some of the most common state-specific rules relate to enrollment in Medicare plans. Not all states have these rights, and the rules vary between states that do have them.

Medicare Advantage plans are private policies that you can buy to replace Original Medicare coverage.

The federal government requires them to cover everything Original Medicare covers in all 50 states. But Medicare Advantage plans may also offer benefits beyond what Original Medicare covers, such as dental, vision, prescription drug and hearing benefits.

The federal government requires an annual open enrollment for Medicare Advantage in every state that coincides with Original Medicare enrollment. This happens every year from Oct. 15 to Dec. 7.

Since 2019, the federal government has also allowed a second open enrollment period for Medicare Advantage from Jan. 1 through March 31. This period allows people with Medicare Advantage to switch to another Medicare Advantage plan or to switch to Original Medicare.

The number of Medicare Advantage plans and their prices vary from state to state. Larger states typically have more options available.

Nationally, Medicare Advantage has become increasingly popular as an alternative to Original Medicare — accounting for 48% of Medicare coverage in the United States as of 2022, according to the Kaiser Family Foundation.

Because Medicare prices, benefits and population vary from state to state, Medicare Advantage may be a popular alternative to Original Medicare in some states compared to others.

As a percentage of the population, only about 1% of Alaskans enrolled in Medicare had Medicare Advantage plans in 2018. But 56% of Medicare beneficiaries in Minnesota were enrolled in a Medicare Advantage plan that same year.

Medicare Part D prescription drug plans are private insurance plans that work with Original Medicare to help cover the costs of your prescription medicine. Many Medicare Advantage plans also provide prescription drug coverage.

Medicare plan prices and plan availability varies from state to state, but all states are required to have open enrollment in Medicare Part D plans at the same time as open enrollment for Original Medicare — Oct. 15 to Dec. 7 every year.

The availability of Medicare Part D plans vary from state to state. The number of plans available in any state in 2022 ranges from 19 choices in New York to 27 choices in Arizona, according to the Kaiser Family Foundation.

The biggest difference between Medicare Part D prescription drug plans from state to state are the premium prices of plans and the number of plans available.

Most states have more than 20 plans for beneficiaries to choose from. But U.S. territories typically have only one to six to choose from.

More significant differences are between the plans themselves. Different formularies — the list of drugs a Part D plan covers — may have a greater impact on whether a particular plan is your best choice.

Since Medicare Part D prescription drug coverage took effect in 2006, it has become increasingly popular.

In 2022, 49 million of the 65 million people — or more than 75% of all Medicare beneficiaries in the United States and its territories — had Part D coverage, according to the Kaiser Family Foundation.

Beneficiaries can choose to enroll in a standalone Medicare Part D prescription drug plan or in a Medicare Advantage plan that includes Part D coverage.

In 2023, 801 plans were available nationwide — a 5% increase over the number available in 2022, according to the Kaiser Family Foundation.

All plans are not available in all states. The numbers range from 19 in New York to 28 in Arizona. Americans living in U.S. territories have fewer to choose from — just one in most territories to six in Puerto Rico.

Monthly premiums and the number of Medicare Advantage and Medicare Part D plans available vary widely across the states.

For example, monthly premiums for a Medicare Advantage plan average $0 in Alaska where there are only two to choose from. But the average is more than $16 with nearly 500 to choose from in California.

Medicare Supplement insurance — also known as Medigap — policies help you cover your out-of-pocket expenses if you have Original Medicare. It’s the only private Medicare-related insurance for which the federal government does not set a mandatory open enrollment period.

You have six months starting with your 65th birthday — and once you’re enrolled in Medicare Part B — to buy a Medigap policy available in your area.

After that, you’re often locked into the Medigap plan you choose. It is difficult or extremely expensive to switch to another Medigap plan in most states.

While Medigap plans are standardized across most of the U.S., there are three states — Wisconsin, Massachusetts and Minnesota — that have different sets of standardized plans allowed by a federal waiver.

Medigap plans are standardized across most states, meaning they offer the same benefits. The exceptions are Wisconsin, Minnesota and Massachusetts. Plans in those states may have options that differ from Medigap plans in other states.

Medicare does not require states to guarantee access to Medigap plans for people under 65 who qualify for Medicare due to a disability such as end-stage renal disease or ALS (also known as Lou Gehrig’s disease). But most states have some type of rule in place giving people with these conditions access.

Medigap plan costs vary widely from state to state — and even within each state. Nationally, the average cost of Medigap premiums was $178 in 2022, and the average deductible was $181, according to Consumer Reports.

State insurance rules affect how Medigap plans are priced in individual states. A state’s cost-of-living may also play a role in a plan’s cost.

Nearly 14.5 million Americans had Medicare Supplement insurance, according to a 2021 study by AHIP, a political advocacy and trade association of health insurance companies.`

Medicare Part B excess charges are additional charges — up to 15% — above the Medicare-approved amount for services. Doctors or other health care providers who do not accept Medicare assignments may bill you for excess charges that Original Medicare will not cover.

The only Medigap plans that cover excess charges are Plan F and Plan G. However, no one enrolled in Medicare on or after Jan. 1, 2020, can purchase Plan F. So, if excess charges are a major concern, Plan G is the only option for coverage against the charges if you are a new Medicare enrollee.

But, eight states ban excess charges. You won’t have to worry about them if you live in these states:

• Connecticut
• Massachusetts
• Minnesota
• New York
• Ohio
• Pennsylvania
• Rhode Island
• Vermont

People with certain disabilities can enroll in Medicare before they turn 65. But, federal law does not require insurers to provide Medigap policies to those under 65.

However, most — not all — require insurers to provide at least one plan to people under 65 who qualify for Medicare because of their disability.

• Alabama
• Alaska
• Arizona
• Indiana
• Iowa
• Nebraska
• Nevada
• New Mexico
• North Dakota
• Ohio
• Rhode Island
• South Carolina
• Utah
• Virginia
• Washington
• West Virginia

Even though these states may not require insurers to provide Medigap coverage to people with disabilities younger than 65, insurers in these states may do so anyway. You can find out if you qualify for Medigap coverage by contacting the State Health Insurance Assistance Program — SHIP — in your state.

If you have Original Medicare, then you will be covered anywhere in the U.S.

Since Original Medicare is a federal program, it provides blanket coverage across the country. But, even in another state, you still have to receive treatment from a doctor who is enrolled in Medicare.

If you have Medicare Advantage, then it will depend on your specific plan. Some plans require you to stay within a network or use certain doctors, limiting you if you travel outside of your network.

If you move to another state or region, you may need to find a new Medicare Advantage plan available in that area. According to CNBC, you will have two months to change and update your plan after you’ve arrived in your new state of residence.

If you have Original Medicare, all you need to do if you move is give Medicare your new address and location info.

The term “snowbird” typically refers to a retiree from the north who lives there in the summers but moves each year to a warmer, southern state during the winter months. Original Medicare will cover their hospital and medical expenses in either state of residence. Medigap plans — which supplement Original Medicare — also work throughout the United States.

But it can be more complicated with Medicare Advantage and Medicare Part D coverage. That’s because you may be limited to using doctors, hospitals and pharmacies in the plans’ networks.

There are Medicare Advantage and Part D plans with national networks. Check with the plan to make sure you have provider options in both areas where you plan to live.

Editor Samantha Connell contributed to this article.