Medicare Coverage for Skin Cancer: Mohs, Immunotherapy & More

Medicare coverage for skin cancer is one of the most misunderstood areas in all of Medicare — and the stakes are high. Skin cancer is the most commonly diagnosed cancer in the United States, and seniors face elevated risk from decades of cumulative sun exposure. What Medicare will and will not pay for depends entirely on whether you are being screened, diagnosed, or treated, and on which part of Medicare applies to a given service.

This guide walks through the full spectrum of skin cancer care under Medicare: from the screening gap many beneficiaries don’t know exists, through biopsies and Mohs surgery, all the way to the immunotherapy drugs that can cost $200,000 or more per year — and why your supplemental coverage choice matters enormously.

The Screening Gap: What Medicare Does NOT Cover

Here is the most important fact in this article: Medicare does not cover routine annual full-body skin cancer screening by a dermatologist.

This surprises many seniors, who assume that if something is a recommended health practice, Medicare will cover it. That is not how Medicare’s preventive benefit works. The program generally covers preventive screenings only when the U.S. Preventive Services Task Force (USPSTF) has assigned them a grade of A or B. As of 2025, the USPSTF has not issued an A or B recommendation for routine skin cancer screening in the general adult population — the evidence on whether screening reduces mortality has been judged insufficient for a strong recommendation. Without that grade, Medicare has no statutory basis to cover the service.

The practical result: if you walk into a dermatologist’s office for a routine full-body mole check and no concerning lesion is found, Medicare will not pay for that visit, and you will owe the full cost — typically $150–$300 or more for a new patient visit to a dermatologist.

What You Can Do Instead

• Perform monthly self-exams. The American Academy of Dermatology provides free guides at aad.org. Use the ABCDEs of melanoma: Asymmetry, Border, Color, Diameter, Evolution.
• Ask your primary care physician to look at your skin during your Annual Wellness Visit. Medicare does cover the Annual Wellness Visit under Part B with no cost-sharing. While a family doctor is not a dermatologist, they can identify suspicious lesions and refer you to one. That referral triggers covered diagnostic care.
• If you notice anything suspicious, make a dermatologist appointment for evaluation of that specific lesion. The moment a suspicious finding exists, the visit becomes diagnostic — and diagnostic visits are covered.

What IS Covered: Diagnostic Visits for Suspicious Lesions

Once a lesion exists that a clinician deems worth evaluating, Medicare Part B covers the dermatologist visit. The visit is coded as an evaluation and management (E&M) service, just like any specialist visit.

Your cost under Original Medicare:

• You must first meet the Part B annual deductible: $257 in 2025
• After the deductible, you pay 20% coinsurance on the Medicare-approved amount
• For a dermatologist visit, the Medicare-approved amount for an established patient office visit might be $130–$200, making your 20% share roughly $26–$40 per visit

This is manageable for a one-time diagnostic visit. The costs grow substantially once biopsy, surgery, or systemic treatment enters the picture.

Biopsy and Pathology Coverage

If the dermatologist finds a suspicious lesion and decides to biopsy it, both the procedure and its pathology interpretation are covered under Part B.

Skin biopsy: The dermatologist uses a shave, punch, or excisional technique to remove tissue for laboratory analysis. This is a Part B procedure, subject to the same 20% coinsurance after your deductible.

Dermatopathology lab interpretation: The tissue sample must be read by a pathologist, often a dermatopathologist who specializes in skin tissue. This professional service is billed separately and is also covered under Part B at 80/20 after the deductible.

Typical patient cost without Medigap: A biopsy procedure may have a Medicare-approved amount of $150–$300. The separate pathology read might be $80–$150. Without supplemental coverage, you could pay $50–$90 in coinsurance for biopsy plus pathology — a reasonable amount, but one that grows when multiple lesions are biopsied in a single visit or over multiple visits.

If you have a Medigap plan like Plan G, it covers your 20% coinsurance on all Part B services, meaning your out-of-pocket for biopsy and pathology is $0 after you have satisfied the annual deductible.

Mohs Micrographic Surgery

Mohs surgery is the gold standard for removing basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) in high-risk anatomical locations: the face, head, neck, hands, feet, and genitalia. Medicare Part B covers Mohs surgery, and understanding how it works helps explain why it is so valuable — and why the cost can add up.

How Mohs Works

A Mohs-trained surgeon removes thin layers of tissue one stage at a time. After each layer is excised, the surgeon immediately processes and examines it under the microscope in an on-site lab. If cancer cells appear at the margin, another layer is removed and examined. The process continues until the margin is clear. This staged excision with real-time pathology achieves the highest cure rates for BCC and SCC while sparing the maximum amount of healthy tissue — critical for lesions near the eyes, nose, lips, or ears.

A straightforward Mohs case on the nose, for example, might require two stages, reconstruction, and a total procedure time of three to five hours.

Medicare Coverage and Costs

Medicare reimburses Mohs surgery using a per-stage global surgical fee structure. The global fee covers the surgery itself, the intraoperative pathology, and routine follow-up care within the standard postoperative period. Reconstruction (flaps, grafts) is billed separately.

• Medicare-approved global fee for Mohs, first stage: approximately $800–$1,100 (amount varies by geographic area and facility type)
• Each additional stage: approximately $300–$500
• Reconstruction: billed separately, 20% coinsurance applies

Illustrative example: A two-stage Mohs procedure with a local flap reconstruction might have a total Medicare-approved amount of $2,000–$3,500. Without supplemental coverage, you would pay 20% — roughly $400–$700 for a single procedure. That is a meaningful figure, and it can be repeated if you have multiple lesions treated in the same year.

For a patient with Medigap Plan G, the entire 20% is covered after the deductible. Given that many seniors with a history of BCC or SCC return annually for new lesions, Medigap coverage can save hundreds of dollars per year just from Mohs procedures — independent of the far larger savings it generates on systemic therapy.

Standard Surgical Excision

Not every skin cancer requires Mohs. For lower-risk lesions — BCC or SCC on the trunk or extremities, in smaller sizes, with well-defined borders — standard surgical excision with clear margins is the appropriate treatment and is covered under Part B.

Standard excision involves removing the lesion with a margin of normal-appearing skin (typically 4–10 mm depending on lesion type and location) and sending the specimen to a pathology lab. Because the pathology is interpreted after the procedure, a second surgery may be needed if margins are not clear — unlike Mohs, where margins are confirmed in real time.

Cost-sharing follows the same 20% coinsurance structure under Part B.

Melanoma Surgery

Melanoma requires more aggressive surgical management than the common keratinocyte cancers (BCC, SCC). Depending on the stage and setting, Medicare coverage shifts between Part A and Part B.

Wide local excision (WLE): The primary treatment for melanoma. The lesion is removed with wider margins than for BCC or SCC, often 1–2 cm depending on tumor thickness. If performed as an outpatient procedure (which is common for thin melanomas), Part B covers it at the standard 80/20 split.

Sentinel lymph node biopsy (SLNB): For melanomas of intermediate thickness (0.8–4 mm), SLNB is standard of care to check whether cancer has spread to regional lymph nodes. This is often performed in the same surgical session as WLE. SLNB requires nuclear medicine imaging (lymphoscintigraphy) to map the sentinel node, blue dye injection, and surgical excision of the sentinel node(s). Part B covers this when done outpatient; Part A covers it if the patient is admitted.

Lymph node dissection: If sentinel nodes are positive, completion lymph node dissection may be considered. This is a larger surgical procedure and is often performed as an inpatient surgery — covered under Part A, subject to the Part A hospital deductible ($1,676 per benefit period in 2025).

Inpatient vs. outpatient: The setting determines which Medicare part pays. Outpatient surgeries fall under Part B. Inpatient admissions fall under Part A. For melanoma patients, the distinction matters: Part A’s deductible is per benefit period, while Part B’s is annual. Understanding which part is billing helps you anticipate costs and evaluate the value of supplemental coverage. See Medicare Advantage vs. Original Medicare for how these rules differ under Medicare Advantage plans.

Radiation Therapy for Skin Cancer

Radiation therapy is covered under Part B for skin cancer when it is medically necessary — for example:

• Unresectable lesions: tumors too large, too extensive, or located in anatomical areas where surgery would cause unacceptable functional or cosmetic damage
• Adjuvant radiation: delivered after surgery for high-risk SCC or melanoma to reduce recurrence risk at the surgical site or regional lymph nodes
• Electron beam radiation: a specialized form used specifically for superficial skin lesions

Part B covers radiation therapy services at 80/20 after the deductible. A full course of radiation therapy (often 25–30 fractions over five to six weeks) can have a total Medicare-approved amount of $15,000–$40,000 or more, making your 20% share $3,000–$8,000 without supplemental coverage. This is another area where Medigap Plan G pays for itself quickly.

Prescription Topical Treatments Under Part D

For actinic keratoses (pre-cancerous lesions) and superficial BCC, dermatologists often prescribe topical medications that you apply at home. These are oral/topical prescription drugs covered under Medicare Part D, not Part B.

Fluorouracil cream (5-FU / Efudex, Carac): The most widely used topical treatment for actinic keratoses. Applied for two to four weeks, it causes inflammation and destruction of abnormal cells. Also FDA-approved for superficial BCC. Generic versions are available, and cost through Part D is typically $30–$100 per month depending on your plan’s formulary tier.

Imiquimod (Aldara, Zyclara): An immune response modifier used for actinic keratoses and superficial BCC. Applied several times per week for several weeks. Brand-name versions are expensive, but generic imiquimod has become widely available. Part D cost varies significantly by plan.

Diclofenac gel (Solaraze): Used for actinic keratoses. Less commonly used than 5-FU or imiquimod.

The key point: if you rely solely on Part B for your coverage understanding, you may be surprised that these topicals bill through Part D. If you have a standalone Part D plan or a Medicare Advantage plan with drug coverage, verify your plan’s formulary and preferred pharmacy network to minimize cost. See Medicare Part D Explained for how formularies, tiers, and out-of-pocket phases work.

Systemic Treatments: Where the High-Cost Action Is

Advanced and metastatic skin cancer — particularly melanoma — has been transformed by immunotherapy and targeted therapy over the past decade. The drugs that produce these outcomes are extraordinarily expensive, and the split between Part B (infused drugs) and Part D (oral drugs) has major financial implications.

Part B: Infused and Injected Systemic Treatments

Drugs administered by injection or infusion in a clinical setting (physician’s office, hospital outpatient department, or infusion center) are billed under Part B as “incident to” or as separately billable drugs. You pay 20% coinsurance with no cap — meaning your out-of-pocket exposure rises with the drug’s price.

Checkpoint inhibitors for melanoma:

• Pembrolizumab (Keytruda): A PD-1 inhibitor approved for melanoma (adjuvant, unresectable, and metastatic). Administered by IV infusion every three or six weeks. List price: approximately $8,000–$10,000 per infusion. Over a year of treatment, total drug cost can exceed $200,000. Your 20% coinsurance under Original Medicare: $40,000–$50,000 per year or more — without a cap.
• Nivolumab (Opdivo): Another PD-1 inhibitor approved for melanoma, including adjuvant use after surgery. Similar pricing and cost-sharing structure to pembrolizumab.
• Ipilimumab (Yervoy): A CTLA-4 inhibitor, often combined with nivolumab for metastatic melanoma (the “nivo + ipi” combination is standard of care for many patients). Ipilimumab alone can cost $30,000–$50,000 per infusion; combination regimens carry even higher costs.
• Cemiplimab (Libtayo): A PD-1 inhibitor approved specifically for cutaneous squamous cell carcinoma (CSCC) and for advanced BCC. Patients with locally advanced or metastatic CSCC who are not surgical candidates may receive cemiplimab infusions — billed under Part B.

Why this makes Medigap Plan G extraordinarily valuable for skin cancer patients:

Without supplemental coverage, 20% of $200,000 in annual immunotherapy costs is $40,000 — and that can recur year after year during treatment. With Medigap Plan G, the 20% Part B coinsurance is fully covered after you pay the annual deductible ($257 in 2025). For a patient receiving Keytruda, Medigap Plan G can save $30,000–$50,000 per year in out-of-pocket drug costs alone.

This is not a hypothetical. Melanoma patients who respond well to immunotherapy may remain on treatment for one to two years or longer. The cumulative savings from Plan G over a full treatment course can easily reach $60,000–$100,000.

Part D: Oral Targeted Therapies

Some systemic skin cancer treatments come in pill form. These fall under Part D, not Part B. The Medicare Prescription Drug Improvement and Modernization Act and subsequent legislation (including the Inflation Reduction Act of 2022) have changed the out-of-pocket landscape for Part D substantially.

BRAF/MEK inhibitors for BRAF-mutant melanoma:

Approximately 40–50% of cutaneous melanomas harbor a BRAF V600 mutation. These tumors respond to BRAF inhibitors, often combined with MEK inhibitors.

• Dabrafenib (Tafinlar) + trametinib (Mekinist): The most widely used BRAF/MEK combination. Both are oral pills. Retail price: approximately $10,000–$15,000 per month for the combination. Under Part D, these are typically Tier 4 or Tier 5 specialty drugs.
• Vemurafenib (Zelboraf) + cobimetinib (Cotellic): An alternative BRAF/MEK combination, also oral. Similar price range.

Starting in 2025, the Inflation Reduction Act capped Medicare Part D beneficiary out-of-pocket costs at $2,000 per year (the new catastrophic cap). For a patient on a $12,000/month BRAF/MEK combination, this cap is transformative — you hit $2,000 in out-of-pocket cost within weeks of starting therapy, after which the drug is effectively free for the rest of the year. Compared to prior years when patients could owe tens of thousands in Part D cost-sharing, this is a major protection.

See Medicare Part B vs. Part D Drugs for a deeper explanation of how to identify which part covers a given drug — a practical skill for anyone navigating complex cancer treatment.

Hedgehog pathway inhibitors for advanced BCC:

• Vismodegib (Erivedge): An oral smoothened inhibitor approved for locally advanced and metastatic BCC. Taken daily as a pill. Part D drug. Retail price exceeds $10,000/month; the $2,000 annual cap applies here too.
• Sonidegib (Odomzo): Another hedgehog pathway inhibitor for locally advanced BCC. Oral, Part D.

Both vismodegib and sonidegib are options for patients whose BCC is unresectable or has recurred after surgery and radiation — situations where surgery or topical therapy is no longer sufficient.

Hospital Admissions: Part A Cost-Sharing

Complex skin cancer surgeries (particularly for melanoma with lymph node involvement) and some systemic therapy initiations may require inpatient hospitalization. Part A governs these stays:

• Part A deductible: $1,676 per benefit period in 2025
• Days 1–60: $0 coinsurance per benefit period (after deductible)
• Days 61–90: $419/day coinsurance
• Lifetime reserve days (91+): $838/day

A short inpatient surgical stay (two to four days) typically costs you the Part A deductible alone — $1,676. A Medigap Plan G covers this deductible in full, leaving you with $0. For financial planning purposes, factoring in potential hospitalizations when estimating healthcare costs in retirement is essential.

Medicare Advantage Considerations

Medicare Advantage (MA) plans must cover all services that Original Medicare covers but may impose different cost-sharing, prior authorization requirements, and network restrictions.

For skin cancer patients considering MA, key questions include:

• Is your dermatologist in-network? Mohs surgeons and dermatologic oncologists may not participate in all MA networks.
• Does the plan require prior authorization for Mohs surgery or immunotherapy? PA requirements can delay time-sensitive treatment.
• Does the plan use step therapy for immunotherapy? Some MA plans require trials of less expensive treatments before approving pembrolizumab, even when pembrolizumab is the medically appropriate first-line choice. This is particularly problematic for melanoma, where treatment delay can allow rapid progression.
• What is the out-of-pocket maximum? MA plans have annual out-of-pocket maximums (up to $9,350 for in-network services in 2025). Original Medicare has no cap; Medigap fills that gap. Review Medicare Advantage vs. Original Medicare to compare these structures directly.

For patients at high risk for skin cancer — prior skin cancer diagnosis, extensive UV exposure history, immunosuppression — Original Medicare paired with Medigap Plan G is generally the more financially protective choice due to the uncapped 20% coinsurance exposure on potentially expensive immunotherapy.

Practical Financial Guide: How Coverage Type Changes Everything

The same skin cancer treatment can cost dramatically different amounts depending on your Medicare coverage structure. Here is how the math works across three common scenarios.

Scenario 1: Diagnostic visit + biopsy (any coverage type) Small lesion, one biopsy, pathology read. Total Medicare-approved amount: ~$500. Your cost: $100 (20% coinsurance) under Original Medicare. With Medigap Plan G: $0 after deductible. With MA: depends on plan copays, often $30–$75.

Scenario 2: Mohs surgery, two stages, no reconstruction Total Medicare-approved amount: ~$1,800. Your cost under Original Medicare: ~$360. With Medigap Plan G: $0 after deductible. With MA: depends on surgical copay structure, often a flat $300–$500.

Scenario 3: Pembrolizumab immunotherapy, one year of treatment Total Medicare-approved amount: ~$175,000–$200,000+. Your cost under Original Medicare alone: $35,000–$40,000+. With Medigap Plan G: $257 (the annual Part B deductible, nothing more). With MA: capped at the plan’s annual out-of-pocket maximum ($9,350 or less for in-network), but subject to prior authorization and possible step therapy.

The financial protection Medigap Plan G provides for immunotherapy patients is extraordinary. If there is any realistic chance of receiving checkpoint inhibitor therapy, securing Plan G before that treatment begins — ideally during your initial Medicare enrollment window when insurers cannot charge higher premiums for pre-existing conditions — could be the most financially significant healthcare decision of your retirement.

Summary Cost Comparison Table

Frequently Asked Questions

Can I get a free skin cancer screening anywhere? Yes. The American Academy of Dermatology sponsors free skin cancer screenings in communities across the country each year, typically in May (Skin Cancer Awareness Month). Visit aad.org to find events near you. These are not Medicare-billed — they are volunteer-provided screenings at no cost to attendees.

What if my dermatologist says a suspicious lesion is benign and documents it as a routine check — will Medicare still pay? No. If no suspicious lesion warranted evaluation, the visit is considered a screening, not a diagnostic service, and Medicare will not cover it. Your dermatologist’s medical coding must reflect a diagnosed condition or a complaint requiring evaluation for the visit to be covered.

Does Medicare cover immunotherapy if I have a clinical trial enrollment? Medicare covers routine costs of clinical trial participation for approved trials. Routine costs include the medical care you would receive even outside the trial. The experimental drug itself may be provided free by the trial sponsor. Talk to your oncology team about how trial enrollment interacts with your Medicare coverage.

Should I enroll in Medigap if I already have skin cancer? If you are newly eligible for Medicare (turning 65 or enrolling for the first time), you have a guaranteed-issue window during which Medigap insurers cannot deny coverage or charge higher premiums for pre-existing conditions, including existing skin cancer. Outside that window, most states allow underwriting. Act during your initial enrollment period.

Key Takeaways

Medicare coverage for skin cancer is both broad and nuanced. The gap that catches most beneficiaries off guard is the absence of routine screening coverage — but once a suspicious lesion is present, Part B covers diagnosis and most treatment comprehensively. The financial turning point is systemic therapy: checkpoint inhibitors under Part B carry unlimited 20% coinsurance exposure, making Medigap Plan G potentially worth tens of thousands of dollars per year for patients receiving immunotherapy.

For a complete picture of how drug costs work in Medicare, review Medicare Part D Explained and Medicare Part B vs. Part D Drugs. For broader retirement healthcare cost planning that incorporates cancer treatment risk, see Healthcare Costs in Retirement.

Coverage rules, deductibles, and drug prices are based on 2025 Medicare data. These figures update annually. Verify current amounts at medicare.gov or with your State Health Insurance Assistance Program (SHIP) counselor.