Hougom Insurance Agency

Medicare · Wisconsin

Medicare Supplement & Part D: how they work together in Wisconsin

Key takeaways

  • Original Medicare leaves you with significant out-of-pocket exposure — a Wisconsin Medicare Supplement (Medigap) fills those gaps
  • Medicare Supplement does not cover prescription drugs — you need a separate Part D plan
  • In 2026, Part D has a $2,100 out-of-pocket cap — a major improvement for people on expensive medications
  • Wisconsin uses its own Medigap system (Basic Plan + optional riders), not the national Plan A–N letter system
  • Together, Original Medicare + Wisconsin Supplement + Part D gives you comprehensive coverage with no provider network restrictions
$2,100 Part D out-of-pocket drug cap in 2026 CMS Medicare & You, 2026
$1,736 Part A hospital deductible per benefit period (covered by Supplement) CMS, 2026
20% Part B coinsurance Original Medicare leaves you to pay (covered by Supplement) Medicare.gov, 2026

Why you typically need both

Original Medicare (Part A + Part B) is a strong foundation, but it has two significant gaps that most people on Original Medicare choose to fill:

Gap 1 — Medical cost-sharing

Original Medicare covers 80% of most medical costs. The remaining 20% — plus hospital deductibles, daily hospital coinsurance, and excess charges — is your responsibility, with no annual cap. A Wisconsin Medicare Supplement fills these gaps, giving you predictable monthly costs instead of unpredictable exposure.

Gap 2 — Prescription drugs

Original Medicare does not cover most outpatient prescription drugs. Medicare Supplement does not add drug coverage either. Without a Part D plan, you pay 100% of prescription costs out of pocket. A standalone Part D plan closes this gap, and in 2026 your annual drug costs are capped at $2,100.

Wisconsin Medicare Supplement (Medigap)

Wisconsin does not use the national Medicare Supplement letter system (Plan G, Plan N, etc.) that applies in 47 other states. Instead, Wisconsin has its own state-standardized system governed by the Wisconsin Office of the Commissioner of Insurance (OCI).

The Wisconsin Basic Plan — your required foundation

Every Wisconsin Medigap policy must include the Basic Plan. It covers:

  • Medicare Part B coinsurance (the 20% Original Medicare doesn't pay)
  • Part A hospital coinsurance for days 61–150 ($434/day in 2026)
  • 365 additional lifetime hospital days after Medicare benefits are exhausted
  • First 3 pints of blood per year
  • Hospice care coinsurance

Common rider combinations

You add optional riders to the Basic Plan to build your coverage level. The most common combination for La Crosse area clients:

Most popular — equivalent to national Plan G
Basic Plan + Part A Deductible Rider ($1,736 per benefit period) + Part B Excess Charges Rider (extra 15% from non-participating providers)

Premiums for this combination typically run $80–$180/month for a 65-year-old in La Crosse County, varying by carrier. Shopping carriers for identical coverage is the single most effective way to reduce your premium.

Full Wisconsin Medicare Supplement guide — Basic Plan, riders, and WI vs. national plans explained →

Medicare Part D prescription drug coverage

Part D is a standalone plan you purchase from a private insurer to add drug coverage to Original Medicare (or to a Medicare Supplement setup). Plans vary by premium, deductible, formulary (the list of covered drugs), and pharmacy network. The 2026 benefit structure:

Phase How it works What you pay
Deductible You pay 100% of drug costs up to the annual deductible (up to $590 in 2026, though many plans have $0 deductible for preferred generics). Up to $590
Initial coverage You pay your plan's copay or coinsurance for covered drugs. Your plan and manufacturer discounts apply. Copays / coinsurance
Out-of-pocket cap Once your true out-of-pocket drug costs hit $2,100 in 2026, your plan pays 100% of covered drug costs for the rest of the year. $0 (after cap)

2026 CMS figures. The $590 deductible is the maximum allowed; many plans offer lower deductibles or waive it for certain tiers. Confirm current year amounts at Medicare.gov.

What to look for when choosing a Part D plan

  • Formulary — confirm your current medications are covered at a favorable tier
  • Pharmacy network — verify your preferred pharmacy is in-network (preferred pharmacy = lower copays)
  • Premium vs. cost-sharing tradeoff — a $0-premium plan can cost more total if your drugs land in expensive tiers
  • Annual review — formularies and premiums change every year; review each fall during AEP (Oct 15 – Dec 7)

How the three layers work together

Layer 1
Original Medicare (Part A + Part B)

Pays 80% of approved medical costs, hospital coverage, preventive care. Foundation for everyone on this track.

Layer 2
Wisconsin Medicare Supplement

Covers the 20% Part B coinsurance, hospital deductibles, and other gaps Original Medicare leaves. No networks — see any Medicare provider in the U.S.

Layer 3
Part D Prescription Drug Plan

Covers outpatient prescription drugs. $2,100 out-of-pocket cap in 2026. Choose the plan whose formulary best matches your medications.

Result: Predictable monthly costs (your premiums), no provider network restrictions, prescription drug coverage with a hard annual cap — and the freedom to see any Medicare provider nationwide including Gundersen Health System, Mayo Clinic, and any specialist.

Enrollment timing — don't miss your windows

Medicare Supplement

Best window: Your 6-month Medigap Open Enrollment Period — starts when you enroll in Part B at 65. During this window, Wisconsin carriers must accept you at standard rates regardless of health history.

After this window, you may face health underwriting — carriers can decline you or charge more based on pre-existing conditions.

Part D

Initial enrollment: Enroll when you first become Medicare-eligible, even with few prescriptions now. Late enrollment without creditable coverage triggers a permanent penalty of 1% per month you went without it.

Annual changes: Switch plans each fall during Annual Enrollment Period (Oct 15 – Dec 7). Changes take effect Jan 1.

Medicare Supplement & Part D FAQs

Do I need both a Medicare Supplement and a Part D plan?

If you choose Original Medicare plus a Wisconsin Medicare Supplement (Medigap), you almost certainly need a separate Part D plan — Medicare Supplement does not cover prescription drugs. Without Part D, you pay 100% of drug costs out of pocket. The main exception: if you have creditable drug coverage from another source (VA, employer), you may be able to delay Part D without a late-enrollment penalty.

Can I use Medicare Supplement and Part D together?

Yes — this is exactly how most Wisconsin Medigap users structure their coverage. Original Medicare (Part A + Part B) is your foundation. A Wisconsin Medicare Supplement covers the out-of-pocket costs Original Medicare doesn't pay (coinsurance, deductibles, etc.). A standalone Part D plan covers prescription drugs. Together, the three layers give you comprehensive, predictable coverage with no provider networks.

What is the Part D out-of-pocket cap in 2026?

In 2026, the Medicare Part D out-of-pocket cap is $2,100 for covered drugs. The Inflation Reduction Act introduced this cap starting in 2025 at $2,000 — before that, there was no true cap. Once you hit $2,100 in true out-of-pocket drug costs in a calendar year, your Part D plan pays 100% of covered drug costs for the rest of the year. This makes Part D significantly more valuable for people on expensive medications.

What does Wisconsin's Medicare Supplement cover that national plans don't?

Wisconsin doesn't use the national Plan A–N letter system. Instead, Wisconsin has its own state-standardized system: a mandatory Basic Plan (covering Part B coinsurance, Part A hospital coinsurance, 365 extra hospital days, blood, and hospice) plus optional riders you add on. The most common combination — Basic Plan + Part A Deductible rider + Part B Excess Charges rider — is functionally equivalent to national Plan G.

When should I enroll in Part D?

You should enroll in Part D when you first become eligible for Medicare (at 65), even if you don't take many medications now. If you delay enrollment without creditable coverage from another source, you'll face a permanent late-enrollment penalty: 1% of the national base beneficiary premium for every month you went without coverage. The penalty lasts as long as you have Part D.

Can I switch my Part D plan each year?

Yes — during the Annual Enrollment Period (October 15–December 7), you can switch Part D plans. Changes take effect January 1. This matters because formularies (the list of covered drugs) and premiums change each year. We review your medications against available Part D formularies each fall to make sure your plan still makes sense.

How much does a Wisconsin Medicare Supplement cost in the La Crosse area?

For a 65-year-old in La Crosse County, a Basic Plan + Part A Deductible + Part B Excess Charges rider combination typically runs $80–$180/month depending on the carrier. Adding a Part D plan typically costs $0–$60/month depending on your drug needs and the plan's formulary. Total monthly cost for both is often $100–$220 for a 65-year-old — compared to $0 for some Medicare Advantage plans, but with no network restrictions and more predictable costs.

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Get your Supplement + Part D combination reviewed by a local advisor

We compare Wisconsin Medigap carriers and Part D formularies side-by-side for your specific medications, your doctors, and your budget. One conversation — both covered.

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