Update: Compare costs and coverage with Medicare plans

The Medicare open enrollment period for 2026 opened October 15 and runs until December 7. During this period, you can switch between Medicare Advantage and Original Medicare, change from one Medicare Advantage plan to another, or join, change, or drop a Medicare Part D prescription drug plan. Changes made during this period go into effect on January 1, 2026. Remember that just because one Medicare plan worked for you last year doesn’t mean that plan will work again for you this year.

“It is essential for Medicare beneficiaries to understand the plan in which they are enrolling,” said Stephanie Steele, Immune Deficiency Foundation (IDF) director of payer relations and policy.

“I believe the most important changes to Medicare this year will be increased premiums and deductibles, and automatic enrollment in the Medicare Prescription Payment Plan for those on Original Part D Medicare. These changes will affect how beneficiaries manage their healthcare costs and coverage options in 2026.”

Medicare Part B premiums are estimated to cost $206 a month in 2026, a rise from $185 a month in 2025. In addition, the projected Medicare Part B deductible for 2026 is $288, an increase from $257 in 2025.

The average Part D premium is projected to decrease from $38 per month in 2025 to $34 per month in 2026. However, the Part D deductible maximum will increase from $590 in 2025 to $615 in 2026. While patients are responsible for co-pays and deductibles, new this year is an annual out-of-pocket cap of $2,100. Once a patient hits that threshold, they won’t have to pay any more for their medicine for the year.

Another change in 2026 is that people who sign up for Medicare Part D will be automatically enrolled (unless they opt out) in the Medicare Prescription Payment Plan (MPPP), which allows them to spread out payment for their prescription drugs over a year.

If you choose to enroll in a Medicare Advantage plan, contact the plan before enrolling to see if your Ig replacement therapy is covered. Note that, currently, the Medicare.gov comparison tool only lists intravenous Ig (IVIG) replacement therapy covered under Part D, but some Medicare Advantage plans do offer subcutaneous Ig (SCIG) replacement therapy covered under Part B. You have to contact plans directly and ask for a full list of the Ig products they cover to get this information.

Another important date is the Medicare Advantage open enrollment period from January 1 to March 31, 2026. If you are enrolled in a Medicare Advantage plan, you can switch to another Medicare Advantage plan or disenroll from your Medicare Advantage plan and return to Original Medicare.

Original Medicare also has a general enrollment period for Medicare Part A and Part B from January 1 to March 31, 2026. This period is for individuals who didn't enroll when they were first eligible and want to sign up for Medicare Part A or Medicare Part B. There may be a penalty for late enrollment if you don't sign up when you're first eligible.

Expert Medicare advice

IDF Community Resource Manager Angie Kotarski fields an average of one call per day about Medicare coverage. Most people have questions about how Medicare covers their Ig replacement therapy, as they transition from commercial insurance to Medicare.

“Medicare coverage for Ig can be very confusing for those with PI who use the treatment,” said Kotarski.

Kotarski said that Medicare covers Ig replacement therapy based on a person’s diagnosis code. Medicare Part B covers specific diagnoses at 80%, after the yearly deductible. A person’s Medigap supplemental policy or secondary insurance should then cover the remaining 20%. Keep in mind that Medigap is only available to people who don't have insurance from their employer in retirement. If a person’s diagnosis isn’t on the PI diagnoses list, Ig replacement therapy will be covered under Medicare Part D.

If you have a Medicare Advantage Plan, the Medicare Advantage Plan determines if claims are paid under Medicaid Part B or Part D.

“Compare all the costs, not just the premiums, because Medicare Advantage can be better on paper, but when you look at the out-of-pocket costs, they are higher,” said Kotarski.

Medicare plans vary from state to state and even in counties within a state. State Health Insurance Assistance Programs (SHIP) have trained counselors who can recommend plans that are right for you and help you find answers to your questions about coverage, said Kotarski.

She advises sharing the following points with a SHIP counselor or an insurance plan representative so they can verify coverage or direct you to someone who can.

• Emphasize that your Ig therapy for PI is a medical treatment covered under Medicare Part B, if appropriate. Many of the counselors are used to dealing with Ig therapy covered under Part D for non-PI diagnoses. 
• Regardless of your diagnosis, provide the billing code, or J-code, for your product. Your specialty pharmacy or immunologist’s billing office can provide this code.
• Provide your PI diagnosis code obtained from the IDF list or through the Centers for Medicare & Medicaid Services. If you cannot find your PI diagnosis code, consult your healthcare provider to receive the diagnosis code.

“SHIP counselors are great, but they don’t know about infusion costs. What matters is how it’s billed on your diagnosis, not where you receive your infusions or the route of administration,” said Kotarski.

Kotarski stressed that people with PI who are shopping for Medicare plans should compare their medical needs with the offerings of the health plans and the costs.

“The most important thing to consider when signing up for Medicare would be to do a complete cost analysis between Medicare Advantage and Original Medicare with a supplemental plan, and part D. This complete cost analysis would include premiums and out-of-pocket expenses like your deductible, copays, and coinsurance costs,” said Kotarski.

“Too many people only look at the difference in the monthly premiums when you really need to look at the whole thing.”

Originally published February 6, 2025

If you are currently on Medicare Advantage and the coverage does not provide you with affordable access to medications and medical services, you have a window of opportunity to change to original Medicare.

• The open enrollment period to drop Medicare Advantage and enroll in Original Medicare runs from January 1 to March 31. You may also switch during a period from October 15 to December 7.  Contact Medicare to make the change.

Navigating enrollment for Medicare coverage requires time, and a thorough understanding of the options, with a particular focus on access to providers, medical services, and drugs. Everyone turning 65, including those with primary immunodeficiency (PI), must choose whether to use original Medicare or Medicare Advantage as their health insurance. It's important to examine the benefits and drawbacks of each plan before reaching a decision.

Keep in mind that original Medicare provides more options because Medicare Advantage plans are run by private insurers and have some of the same restrictions/limitations as other private insurance plans, in areas like formularies and networks.

Original Medicare

Original Medicare is a federal health insurance program that offers benefits, some free but most at a cost, to those 65 and older and to those under 65 who meet specific disability criteria. Depending on your plan type, you may receive coverage for services such as primary medical care, hospital stays, or prescription drugs. The coverage is divided into Parts A, B, C, and D, with other letters assigned to Medigap, or supplemental plans.

Most people turning 65 should enroll in original Medicare Part A, even if they receive health insurance from an employer because most don’t pay a premium for the plan. Part A offers coverage for hospitalization, skilled nursing facilities, hospice care, and some home health care. Part B is optional, but most people enrolled in Part A also choose Part B. Part B covers doctor’s office visits, preventive care, scans and tests, medical equipment, and other medically necessary services, including immunoglobulin (Ig) replacement therapy for certain PIs. Enrollees can also enroll in Part D, which covers prescription drugs. Parts B and D, and sometimes A, require premiums.

Because Part B of original Medicare covers only 80% of the cost of covered services (other than preventative services, which are covered at 100%), enrollees often pay a premium to have a Medigap policy, or supplemental plan, cover the remaining 20%. The Medigap policies, sold by private insurance companies, range in price. Having this supplemental insurance is important for Ig coverage, which is costly. Medigap is only for those who don’t have other insurance through an employer or retirement plan to cover the 20%.

Medicare Advantage

In contrast, Medicare Advantage, also known as Medicare Part C, is an option where enrollees choose from private insurance plans for their healthcare needs. Types of Medicare Advantage Plans include Health Maintenance Organizations (HMOs), and Preferred Provider Organizations (PPOs). To join a Medicare Advantage Plan, participants must enroll in Medicare Parts A and B as an administrative step. Premiums vary by plan.

Choosing a plan

When it comes to choosing a plan that best suits the needs of a person diagnosed with PI, it’s important to remember that, unlike original Medicare, Medicare Advantage plans may apply different rules, costs, and restrictions. Consider these differences between original Medicare and Medicare Advantage:

• Provider access: With original Medicare, you have the same benefits at any provider or facility that accepts Medicare, and most doctors do accept Medicare. In contrast, Medicare Advantage plans may limit you to in-network providers and facilities or charge more for out-of-network care. Limiting provider access is especially detrimental to a person with PI who has built a network of care that includes an immunologist and other specialists
• Ig access: Original Medicare allows you to choose the product, and route of administration that is appropriate for you, whereas Medicare Advantage plans may limit your access to Ig. Medicare Advantage plans have formularies of preferred products and may have certain requirements where you have to use the lowest-cost product unless there are medical reasons to step up to the higher-cost product.
• Costs: With original Medicare, you pay a monthly Part B premium and are responsible for a 20% coinsurance cost after meeting your deductible, or you may purchase a Medigap plan to cover those additional costs. Under a Medicare Advantage plan, cost-sharing varies depending on the plan and you usually pay a copay for in-network care. Medicare Advantage plans may charge a monthly premium in addition to the Part B premium. 
• Supplemental insurance: Original Medicare allows you the choice to pay an additional premium for a Medigap policy to cover Medicare cost-sharing. You cannot purchase a Medigap policy if you opt for Medicare Advantage.
• Referrals: Original Medicare does not require referrals for specialists. Medicare Advantage plans may require referrals for specialists.
• Drug coverage: Under original Medicare, you must sign up for a stand-alone Part D plan if you want prescription drug coverage. Under Medicare Advantage, in most cases, the plan provides prescription drug coverage, but you may be required to pay a higher premium. Both plans have formularies.
• Other benefits: Original Medicare does not cover vision, hearing, or dental services.  Medicare Advantage plans may cover additional services, including vision, hearing, and/or dental, but those additional benefits may increase your premium and/or other out-of-pocket costs.
• Out-of-pocket limit: Original Medicare has no out-of-pocket limit, whereas Medicare Advantage plans have a standardized annual out-of-pocket limit.

Immune Deficiency Foundation (IDF) Community Resource Navigator Angela Kotarski said that, in her opinion, original Medicare with a drug plan and a supplemental plan, best fits the needs of most people with PI. People with chronic conditions require the flexibility offered by original Medicare.

“While the Medicare Advantage plans are good for some people, they do pose a lot of restrictions,” she said.

Kotarski also stressed that whether a person chooses original Medicare or Medicare Advantage, they must submit the results of all testing for PI, such as a pneumococcal vaccine challenge, low IgG levels, and a history of recurrent infections results and other diagnostic evaluations, to the plan administrators. Otherwise, enrollees may have to pay out-of-pocket for the health care services or go off of therapy to have these tests redone.

“It’s extremely important that that documentation is on file,” said Kotarski.