Medicare Advantage vs Original Medicare for cancer

The Medicare Advantage (Part C) vs Original Medicare plus Medigap decision is one of the most consequential insurance choices a cancer patient can make. The two options have different cost structures, different network rules, and different prior-authorization burdens. Which is better depends on the specific treatment plan and where you live.

This guide walks through the trade-offs for cancer patients specifically.

Quick side-by-side

The out-of-pocket question

For cancer patients, this is the largest factor.

Original Medicare without Medigap

Under Original Medicare, Part B has a deductible ($240 for 2024) and 20 percent coinsurance on most services, with no annual out-of-pocket cap. For a cancer patient on expensive Part B drugs (Keytruda at about $76,000 per year per CMS Part B spending data), the 20 percent coinsurance alone can exceed $15,000 per year. Multi-year treatment can run into six figures of patient out-of-pocket.

Original Medicare plus Medigap Plan G

Medigap Plan G covers the Part A deductible, Part B 20 percent coinsurance, and excess charges. For a cancer patient, this means Part B drugs are effectively covered at 100 percent after the Part B deductible. Monthly premium adds roughly $150-$250 depending on state and age.

Medicare Advantage

Medicare Advantage caps annual in-network out-of-pocket at $8,850 for 2024. This is lower than what an unsupplemented Original Medicare beneficiary might pay in a single year, but higher than what a Medigap holder typically pays. Premium is often $0 above the Part B premium.

Network restrictions

Cancer patients often want access to NCI-designated cancer centers (MSKCC, MD Anderson, Dana-Farber, Mayo, and similar) or specific subspecialists. Original Medicare accepts you at any Medicare-participating provider in the U.S. Medicare Advantage plans limit coverage to their contracted network.

If your Medicare Advantage network does not include a center you want to visit:

• Some plans have out-of-network benefits with higher cost-sharing
• Some plans will authorize out-of-network care if in-network providers lack appropriate subspecialty expertise
• Some plans deny coverage, requiring you to switch plans at open enrollment or pay out-of-pocket

If maintaining access to specific centers is important, verify network status before enrolling.

Prior authorization burden

Medicare Advantage plans commonly require prior authorization for:

• Specialist consultations
• Imaging (CT, MRI, PET)
• Specialty drugs, including cancer drugs
• Radiation therapy and stereotactic radiosurgery
• Clinical trial enrollment in some cases

Original Medicare has significantly fewer prior authorization requirements. For time-sensitive cancer treatment decisions, prior authorization delays can matter.

Part D (drug) coverage

Medicare Advantage plans typically include Part D coverage in a single plan. Original Medicare beneficiaries need a separate Part D plan.

Cancer patients on expensive oral drugs (Ibrance, Verzenio, Xtandi, Tagrisso, Lynparza) should review the Part D formulary carefully. Specialty cancer drugs land in the highest tiers with the highest cost-sharing. The Inflation Reduction Act caps total annual Part D out-of-pocket at approximately $3,500 in 2024 and $2,000 in 2025.

When Medicare Advantage is usually the better choice

• You do not need access to providers or centers outside the plan’s network
• You want a predictable annual out-of-pocket cap at $8,850
• You want dental, vision, and hearing benefits included
• You cannot afford or do not qualify for a Medigap policy
• You are comfortable with prior-authorization processes

When Original Medicare plus Medigap is usually the better choice

• You want access to any Medicare-participating provider in the U.S.
• You want to minimize prior authorization friction on imaging and specialty drugs
• You expect high annual drug spending for which Medigap’s coverage of the Part B 20 percent matters
• You can afford the Medigap premium
• You travel frequently or may need care outside your home region

Special considerations for cancer patients

Switching from Medicare Advantage to Original Medicare

You can switch from Medicare Advantage back to Original Medicare during the annual open enrollment period (October 15 to December 7) or during the Medicare Advantage open enrollment period (January 1 to March 31).

Medigap medical underwriting is the catch: in most states, Medigap insurers can require medical underwriting for applications outside your initial eligibility window. Cancer patients seeking Medigap coverage after a diagnosis may be denied or rate-adjusted. A few states (Connecticut, Maine, Massachusetts, New York, and some others) have guaranteed-issue rules year-round.

Plan your enrollment timing carefully. Enrolling in Medigap during your initial eligibility window avoids medical underwriting.

Clinical trials

Both Original Medicare and Medicare Advantage cover routine patient costs of qualifying clinical trials, as the ACA requires. Medicare Advantage plans may require prior authorization; Original Medicare generally does not.

Next

• Does Medicare cover cancer treatment?
• Medicare Part D vs Part B for cancer drugs
• How to appeal a cancer treatment denial
• Drug costs: 15 major oncology drugs