Medicare Supplement vs Advantage When You Have MS and See Dr. Kaplan

Context: a friend in the Kansas City area will soon be eligible for Medicare, has multiple sclerosis, and sees Jeffrey M. Kaplan, MD, at AdventHealth Medical Group Neurology at Roeland Park (5675 Roe Boulevard, Suite 260, Roeland Park, KS 66205; 913-632-2680). He founded the Kansas City MS and Headache Center and is medical director of the AdventHealth MS Infusion Center. This is a decision memo, not a plan recommendation. Numbers are 2026 unless noted. Verify every network and formulary line with the plan and the office before enrolling.

The actual choice

There are two paths. They are not variants of the same product.

1. Original Medicare (Parts A and B) + a Medigap supplement (usually Plan G) + a standalone Part D drug plan. You keep Medicare. Medigap pays most of what Medicare does not. Any doctor or hospital that accepts Medicare is in play, including Dr. Kaplan and the AdventHealth infusion center, with no network and almost no prior authorization.
2. Medicare Advantage (Part C), usually with drugs bundled (MAPD). A private plan replaces Original Medicare. Premiums are often $0 beyond the Part B premium. Care runs through a network, referrals on many HMOs, and prior authorization on expensive services. There is an annual out-of-pocket cap. Extras (dental, vision, hearing, gym) are common.

You cannot have both. Medigap does not pair with Advantage.

2026 anchors

• Part B premium: $202.90 a month. Everyone on either path pays this unless a low-income program covers it.
• Part B deductible: $283.
• Part A deductible: $1,736 per benefit period.
• Medicare Advantage in-network maximum out-of-pocket: up to $9,350. Combined in- and out-of-network can reach about $14,000. Many local plans set a lower cap. The cap is real; it is not small if you land in it.
• Part D out-of-pocket cap: $2,000 in 2025, inflation-indexed to about $2,100 in 2026. This cap applies to both standalone Part D and Advantage drug coverage. It does not cap Part B infusion coinsurance.
• Kansas Medigap is community-rated. Premiums do not rise just because you age. A secondary consumer guide put average Plan G near $135 a month for a 65-year-old in Kansas. Shop the Kansas Insurance Department rate comparison; that average is not a quote.
• Kansas gives under-65 disabled Medicare beneficiaries the same six-month guaranteed-issue Medigap window as people turning 65, at the same premium as a 65-year-old. That is stronger than most states. A second guaranteed-issue window opens at 65 even if you already had Medigap.

Why MS changes the math

MS care is specialist-heavy, imaging-heavy, and drug-heavy. The drugs split across two Medicare benefits, and that split is the whole game.

Part B (medical) infusions and in-office drugs. Ocrevus (ocrelizumab), Tysabri (natalizumab), Briumvi (ublituximab), Lemtrada (alemtuzumab), and Ocrevus Zunovo are administered by a clinician, so they bill under Part B, not the pharmacy benefit. After the $283 deductible, Original Medicare pays 80%. You owe 20% of the Medicare-approved amount with no cap. List prices on these drugs run tens of thousands per year. Consumer analyses put unprotected Ocrevus coinsurance in the several-thousand to roughly $8,000–$10,000 range per year, and monthly Tysabri higher still. Plan G picks up that 20% after the Part B deductible. That is the financial case for Medigap in one sentence.

Part D (pharmacy) drugs. Oral DMTs (dimethyl fumarate, fingolimod, teriflunomide, and brand-only agents) and self-injected Kesimpta generally sit on Part D. The annual cap stops the bleed, but formularies narrowed hard in 2025: generics of older DMTs are widely covered; many brand-only DMTs are on fewer than a quarter of formularies. A JAMA Network Open / PMC analysis of 2025 Part D coverage found brand-name-only DMTs often below 25% formulary placement. Step therapy and annual reauthorization are normal.

Prior authorization. KFF's 2026 Medicare Advantage review: 99% of Advantage enrollees are in plans that require prior authorization for some services; 94% for Part B drugs. Traditional Medicare does not generally require prior authorization and does not allow step therapy on Part B drugs. A 2026 scoping review in the neurology literature tied prior authorization most often to care delays (about 60% of reported consequences) and increased disease activity (about 25%), including MS relapses while patients waited on DMT approval. That is not "Advantage denies MS." It is "Advantage inserts a gate where Original Medicare does not, and the gate has a documented failure mode in this disease."

The doctor. AdventHealth lists Dr. Kaplan as accepting Medicare Part A and/or B and Medicare Supplement policies. It also lists several Kansas City Advantage products: Aetna-Coventry Medicare individual HMO and PPO, Allwell (Wellcare) Medicare Advantage (KS and MO), Blue Medicare Advantage–Kansas City, Cigna HealthSpring Medicare Advantage HMO, Coventry-Aetna Medicare Advantage HMO and PPO, Humana Gold Medicare Advantage, Sunflower AllWell Medicare Advantage, UnitedHealthcare Medicare Advantage, and Medicare Advantage PFFS. The hospital's own disclaimer says the list is reference only and can change. Directories lie. Call the office and the plan with the exact plan ID, and ask specifically about the infusion center, not just the clinic.

Simple pro / con

Original Medicare + Medigap (Plan G) + Part D

Pros

• Dr. Kaplan and the AdventHealth MS infusion center are available if they take Medicare. No network, no referral.
• After the $283 Part B deductible, Plan G covers Medicare coinsurance, including the 20% on Part B infusions. Hospital deductible covered. Costs become a premium problem, not a surprise-bill problem.
• Almost no prior authorization on Medicare-covered services. The neurologist and the patient pick the DMT; the plan does not run step therapy on Part B drugs.
• Benefits are standardized. A Plan G in 2027 is the same contract as a Plan G in 2026. Advantage redesigns every fall.
• Travels. Any Medicare-accepting provider in the country.
• Kansas community rating and a real guaranteed-issue window, including under 65.

Cons

• Higher monthly premium. Plan G in Kansas is often on the order of $100–$200, plus Part B, plus a Part D premium. You pay it in quiet years too.
• No dental, vision, or hearing. Buy those separately or pay cash.
• Part D is a second shopping problem. Brand-only DMTs may be off formulary. The $2,100-ish cap helps; it does not make every drug available.
• The six-month Medigap open enrollment is mostly one-shot. Miss it, and MS is exactly the history underwriters use to decline or rate up. Trial right exists if you try Advantage in the first year and leave. After that, the door often swings one way.
• Medigap does not cap drug costs. Part D does that job.

Medicare Advantage

Pros

• Low or $0 premium beyond Part B. Attractive if cash flow is the constraint and utilization stays moderate.
• One card. Drugs usually included. Dental, vision, hearing, OTC, gym are common sweeteners.
• Hard out-of-pocket cap. Original Medicare alone has none. (Medigap makes that cap mostly irrelevant for medical services.)
• Must cover everything Original Medicare covers, including MS treatment. Some Kansas City plans list Dr. Kaplan. If the specific plan, the clinic, and the infusion site all confirm in-network, Advantage is a workable machine, not a trap.
• Guaranteed issue every year. MS cannot get you rejected from Advantage. It can get you rejected from Medigap later.

Cons

• Network. Leave the plan's list and non-emergency care is not covered (HMO) or costs more (PPO). Directories go stale. Plans can drop hospitals or specialists at renewal.
• Prior authorization on the expensive stuff: 94% of 2026 enrollees face it for Part B drugs. Step therapy on Part B drugs has been allowed in Advantage since 2019. Delays here are not theoretical in MS.
• Copays stack. Specialist visits, MRIs, infusion coinsurance, and hospital daily copays can push a heavy MS year toward the plan's MOOP. A $9,350 cap is protection. It is also a bill.
• Formulary and utilization rules reset annually. A DMT covered this year can move tiers or gain a step edit next year.
• Service area is local. Snowbird or specialist-out-of-town care is emergency-only on many plans.
• Switching back to Medigap later is the hard direction if you are outside a guaranteed-issue window. MS makes underwriting a likely no.

Expert panel

MS neurologist (access camp). The drug and the MRI have to happen on the schedule the disease sets, not the schedule a utilization desk sets. Part B infusions under Original Medicare plus Plan G remove the 20% shock and the step-therapy lever. Keeping a known MS specialist is not a lifestyle preference. Switching neurologists because a network changed is a clinical risk. Default to Medigap if the window is open and the premium is payable.

Medicare broker (cash-flow camp). Advantage wins for people who will not use much care and want dental in the premium. It can also win for an MS patient whose exact plan lists Kaplan and the infusion center, puts the current DMT on formulary at a tolerable tier, and sets a low MOOP. Do not buy that from a TV ad. Buy it from a written confirmation for this plan year. If the premium gap is unaffordable, a PPO with a low MOOP beats going uninsured on the 20%.

Health-policy analyst (KFF / utilization camp). Advantage is not skimpier on paper. It is gated. The 2026 prior-authorization map concentrates on Part B drugs, hospital, SNF, and home health — the exact services a progressing MS patient uses. Denial rates on submitted requests are not catastrophic in aggregate (about 8% denied in 2024), but the delay and the paperwork are the tax, and neurology has case literature of relapses during the wait. Traditional Medicare does not charge that tax.

Skeptical actuary. Medigap is not magic. You prepay the risk. If someone is stable on a cheap generic oral DMT, sees the neurologist twice a year, and never infuses, Advantage can be the lower expected cost for years. The error is pricing the average year and ignoring the tail. MS tails are infusions, relapses, rehab, and a hospital stay. Plan G is tail insurance. Advantage is a cap on the tail plus friction on the way there. Also: community rating in Kansas makes the Medigap premium less ugly over time than in attained-age states. That is a local fact, not a national slogan.

Patient-access reviewer. Part D narrowing is the under-discussed risk on both paths. A 2025 formulary study found brand-only DMTs collapsing off formularies while generics became near-universal. If the current drug is brand-only and has no good generic, the Part D or MAPD formulary search matters as much as the Medigap vs Advantage argument. Manufacturer copay cards generally do not work once you are on Medicare. Patient assistance and Extra Help are the remaining levers.

Critical review

What holds up:

• The Part B 20% with no cap on infusion DMTs is CMS structure, not blog lore. Plan G covering that coinsurance after the deductible is federal standardization.
• KFF's 99% / 94% prior-authorization figures are 2026 enrollment-weighted, not anecdotes.
• Kansas under-65 Medigap access at age-65 rates is real state law, confirmed by insurer-regulatory summaries and the state buyer-guide framework. Federal law does not require this; Kansas does.
• Dr. Kaplan's AdventHealth listing accepts Medicare and supplements, and names specific Advantage contracts. The listing is not a guarantee for a given member ID.

What does not hold up:

• Dollar savings quoted for Ocrevus or Tysabri under Plan G ($8,000–$21,000) come from secondary Medicare sites using assumed Medicare-approved amounts. Direction is right. Treat the dollars as scenarios until the infusion center's Medicare-allowed amount is in hand.
• "Advantage does not cover MS" is false. "Advantage covers MS the same way" is also false.
• Average Kansas Plan G premiums fluctuate by carrier, sex, tobacco, and household discount. Do not budget off a blog average.
• The neurology prior-authorization review documents harm in published studies. It is not a randomized estimate of relapse risk for Kansas City Advantage enrollees.

Practical sequence

1. Confirm Medicare start: turning 65, or disability (24 months on SSDI, or earlier for ALS). The Medigap clock starts when Part B starts, not on the birthday.
2. List current drugs and mark each Part B vs Part D. Infusion center vs pharmacy. This single list decides more than any commercial.
3. If the six-month window is open and the premium is payable, Plan G plus a Part D plan that covers the current oral or self-injected DMT is the robust default for this doctor and this disease.
4. If Advantage is still in the running, get written yes on three items for the exact plan: Dr. Kaplan in network, AdventHealth MS infusion center in network, current DMT on formulary without a step edit you cannot meet. Recheck every Annual Enrollment Period.
5. Kansas SHIP (Senior Health Insurance Counseling for Kansas) is the free, non-commissioned check. Use it. A broker is fine as a second opinion if you ask how they get paid.
6. Do not miss the Medigap window assuming you can "switch later if Advantage is annoying." With MS, later often means underwriting, and underwriting often means no.

Bottom line: for someone with MS who already has a working relationship with Dr. Kaplan and may need infusion DMTs, Original Medicare plus Plan G plus a checked Part D plan buys access and kills the 20% tail. Advantage buys a lower premium and extras, and rents access to that same doctor one plan-year at a time, behind a prior-authorization gate that concentrates on the drugs that matter. Pick the premium you can sustain. Do not pick the commercial.