Medicare 100 Day Rule: SNF Coverage, Costs, and the Three-Day Stay

Your parent needs rehabilitation after a hospital stay in Wisconsin — physical therapy, occupational therapy, skilled nursing care. Medicare covers up to 100 days in a skilled nursing facility, but the rules around qualifying and the costs at each stage catch families off guard.

Here's how the coverage actually works, what it costs, and where the gaps are.

The Three-Day Inpatient Stay Requirement

Before Medicare covers a single day of SNF rehabilitation, your parent must complete three consecutive midnights as a formally admitted inpatient in a hospital. Not three calendar days — three midnights.

The counting matters:

• The day of admission counts if your parent is admitted before midnight
• The day of discharge does not count
• Days spent under observation status do not count — this is the most common way families lose SNF coverage without realizing it

If your parent was admitted Monday evening and discharged Thursday morning, that's three qualifying midnights (Monday, Tuesday, Wednesday). But if they spent the first 36 hours under observation status before being formally admitted, those hours don't count toward the three-midnight threshold.

The 100-Day Coverage Structure

Once the three-day stay is satisfied, Medicare Part A covers SNF rehabilitation in a benefit period structure:

Days 1–20: Medicare pays 100% of the SNF costs. No copay, no coinsurance. This is the window most families plan around — but rehabilitation often extends beyond it.

Days 21–100: Medicare still covers SNF care, but the patient pays a daily coinsurance amount. For 2026, that coinsurance is $204.00 per day. Over the remaining 80 days, that's a potential out-of-pocket exposure of $16,320. Some Medigap supplemental policies cover this coinsurance — check your parent's policy before assuming they owe it.

After day 100: Medicare coverage ends entirely. If your parent still needs skilled nursing, the options are private pay, long-term care insurance, or Medicaid. Wisconsin's average private-pay daily rate for a skilled nursing facility is approximately $352.

When Medicare Cuts Coverage Short

Medicare doesn't guarantee 100 days. Coverage continues only as long as your parent requires "skilled" services — nursing care or therapy that requires the expertise of licensed professionals. The moment the SNF determines your parent has "plateaued" and no longer needs skilled-level care, they can issue a Notice of Medicare Non-Coverage (NOMNC).

The NOMNC must be delivered at least two calendar days before services are scheduled to end. If you disagree with the determination, contact Livanta LLC (Wisconsin's designated QIO) by noon on the day before the planned termination date to file an expedited appeal.

During the appeal review, your parent's coverage continues and they're not financially responsible for the disputed days.

What Counts as "Skilled" Care

This distinction drives every coverage decision. Medicare considers care "skilled" when it requires the judgment or expertise of a licensed nurse or therapist. Examples:

• Physical therapy to restore mobility after a hip fracture
• Occupational therapy to retrain daily living skills after a stroke
• Wound care requiring sterile technique
• IV medication administration
• Complex medication management

Care that a non-professional could provide — assistance with bathing, dressing, eating — is "custodial" and not covered by Medicare, even in an SNF setting.

The Benefit Period Reset

A new benefit period (and a fresh 100-day SNF clock) starts after your parent has been out of a hospital or SNF for 60 consecutive days. If your parent is discharged from an SNF, goes home for 60 days, and is then hospitalized again, the three-day stay requirement and 100-day coverage reset.

This matters for families managing chronic conditions with recurring hospitalizations. Each qualifying hospital stay can trigger a new SNF benefit period.

Planning for Day 101

The transition from Medicare-covered SNF care to whatever comes next is where many Wisconsin families hit a wall. If your parent still needs facility-level care after day 100, the financial exposure is substantial — more than $10,000 per month at private-pay rates.

The Wisconsin Hospital Discharge Guide covers the full continuum: from counting your parent's qualifying midnights at admission through navigating the Medicaid application process when Medicare coverage runs out. It includes an SNF comparison matrix for evaluating Wisconsin facilities and a timeline for every financial decision point along the way.

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