Where did the 100-day rule come from?

It comes from Medicare Part A's coverage of skilled nursing facility (SNF) care. After a qualifying 3-day inpatient hospital stay, Medicare covers up to 100 days in a Medicare-certified SNF. Days 1-20 are paid in full; days 21-100 require a daily co-pay ($209.50 in 2026). After day 100, Medicare's SNF coverage ends for that benefit period. The number comes from a 1965 statutory choice and has never changed.

So how long can Medicare home health actually last?

There is no fixed limit. Home health is paid in 60-day episodes. At the end of each episode, the agency re-certifies the patient's continued eligibility. As long as the patient remains homebound and has a skilled need, the episodes renew indefinitely. Some Medicare patients receive home health for many months across multiple episodes.

Why do so many people think home health has a 100-day cap?

Three reasons. First, the SNF 100-day rule is well known and sounds like it should apply broadly. Second, some discharge planners and even some hospital social workers say it incorrectly. Third, home-health agencies sometimes terminate care prematurely (the 'Improvement Standard' problem), telling families coverage has ended when it should continue. The Jimmo v. Sebelius settlement clarified that maintenance care can still be covered as long as a skilled need exists.

What's the SNF 3-day rule?

To qualify for SNF Part A coverage, the patient must have a hospital stay of at least three consecutive nights as an inpatient. Time in observation status doesn't count, even if the patient slept in a hospital bed for three nights. Families should ask the hospital, in writing, whether the patient is admitted as 'inpatient' or held in 'observation status', the answer determines later SNF coverage.

What happens after Medicare SNF coverage ends (day 100 or earlier)?

The patient either goes home (often with Medicare home health if eligibility holds, or with private-pay or IHSS care), transitions to long-term skilled nursing under Medi-Cal (if Medi-Cal eligible), or returns home with family-provided care. Discharge planning should start by day 60 of the SNF stay, not day 95.

The Medicare 100-day myth: home health vs. SNF

The Medicare 100-day myth, corrected.

The 100-day Medicare rule applies to skilled nursing facility (SNF) care under Part A, not home health. Home health has no fixed end and pays in 60-day episodes that re-certify as long as the patient remains homebound and has a skilled need. The two benefits are routinely confused, and the confusion causes families to plan around a deadline that does not exist.

Two benefits, two settings, one confusing number

Medicare home health and Medicare SNF rehab are completely different. They are separate benefits with separate rules, paid out of different parts of Medicare, delivered in different settings, by different providers, to different categories of patients.

Medicare home health is care delivered at home by a nurse or therapist for a homebound patient with a skilled need. It is paid out of Part A (and sometimes Part B), in 60-day episodes, with no fixed cap, and no co-pay during a covered episode.

Medicare SNF rehab is care delivered in a skilled nursing facility after a qualifying three-day inpatient hospital stay. It is paid out of Part A, capped at 100 days per benefit period, with co-pays starting on day 21.

The 100 days belongs only to SNF rehab. Home health has no equivalent cap.

What the SNF 100-day rule actually says

After a Medicare beneficiary spends at least three consecutive nights as an inpatient in a hospital, they become eligible for Medicare-covered rehabilitation in a skilled nursing facility, if they need daily skilled care (nursing or therapy) related to the condition that was treated in the hospital. Medicare then pays:

Days 1-20: 100%, no co-pay
Days 21-100: Medicare pays most; patient (or Medi-Cal, Medigap, MA cost-share) pays $209.50/day in 2026
Day 101+: Medicare pays nothing

The 3-day rule has a wrinkle: time in “observation status” doesn’t count, even if the patient was in a hospital bed for three nights. Families should confirm inpatient admission, in writing, before assuming SNF eligibility.

Why the misconception persists

Home-health agencies sometimes terminate coverage prematurely, citing the “Improvement Standard”, the idea that Medicare only pays for improvement, not maintenance. This was a long-standing practice that the 2013 Jimmo v. Sebelius settlement explicitly invalidated. Medicare home health can cover care intended to maintainthe patient’s condition and prevent or slow decline, not just care intended to improve. Many agencies still incorrectly apply the old rule.

The fix: ask for the determination in writing, request a Notice of Medicare Non-Coverage if the agency is discontinuing, and appeal to the Beneficiary and Family Centered Care Quality Improvement Organization (BFCC-QIO). Many denials are reversed on appeal.

How this matters for California families in practice

A typical sequence and the right plan:

Hospital admission (3+ inpatient nights). Confirm inpatient status. This unlocks Part A SNF rehab eligibility.
SNF rehab (up to 100 days). Discharge planning should begin by day 30, not day 90. The patient transitions either home or to long-term skilled nursing.
If going home with continued need: Medicare home health begins, paid in 60-day episodes. No cap. Continues as long as homebound + skilled need.
If home health stops: not because of a deadline, but because the skilled need ends. Transition to IHSS / private-pay home care / LTC insurance / VA / etc.
If staying in SNF past day 100: Medicare stops paying. Medi-Cal long-term care coverage begins for eligible members.

What this means for planning

Families planning around “100 days” often make two specific mistakes. First, they rush home-health discharge under the false assumption that coverage is about to end, when in fact it may continue for months. Second, they delay private-pay arrangements during SNF rehab assuming they have 100 days, when in fact most patients are discharged earlier and the planning should start at day 30.

The right mental model: Medicare home health is event-driven (ends when the skilled need ends), not date-driven. Medicare SNF rehab is date-driven (caps at 100 days) but most patients are discharged earlier than 100 days based on clinical progress.

Related coverage and next steps

This page explains coverage and eligibility, not medical advice. Talk to a licensed clinician about care decisions, and to a benefits counselor about your specific plan. California Care Compass does not place referrals on Coverage pages.