One of the most misunderstood aspects of Medicare is the “100-day rule” for nursing home and skilled nursing facility (SNF) coverage. Many families are blindsided when Medicare stops paying — sometimes much sooner than expected. Understanding how this benefit actually works can save you thousands of dollars and prevent a care crisis.
The 100-Day Rule: What Medicare Actually Covers
Medicare Part A covers skilled nursing facility care for up to 100 days per benefit period — but coverage is structured in three phases:
| Days in SNF | Medicare Covers | You Pay |
|---|---|---|
| Days 1–20 | 100% of the approved amount | $0 (after Part A deductible) |
| Days 21–100 | All costs above daily co-insurance | $194.50/day (2025) |
| Day 101+ | Nothing | 100% of all costs |
The 3-Day Hospital Stay Requirement
Before Medicare will cover SNF care, you must have been an inpatient (formally admitted) at a hospital for at least 3 consecutive calendar days. This is called the “qualifying stay.”
Critical warning: If the hospital keeps you under “observation status” — which is outpatient care even if you sleep there for multiple nights — those days do NOT count toward the 3-day requirement. Always ask your hospital whether you are admitted as an inpatient or kept under observation.
When Medicare Stops Before Day 100
The 100-day limit is a maximum, not a guarantee. Medicare stops paying whenever the patient no longer needs skilled care — which often happens well before day 100. This occurs when:
- A therapist determines the patient has reached their maximum functional level (plateau)
- The skilled nursing need ends (wound heals, IV therapy concludes)
- The patient is discharged home
Important: Following the 2013 Jimmo v. Sebelius settlement, Medicare cannot deny SNF coverage solely because a patient isn’t improving — as long as skilled care is needed to maintain function or prevent decline. If coverage is denied prematurely, request a formal demand bill and appeal.
What Is a Benefit Period?
The 100-day limit applies per benefit period — not per calendar year. A benefit period begins when you are admitted to a hospital or SNF and ends when you have been out of both for 60 consecutive days.
This means:
- If you use SNF coverage, go home, then return to the hospital after a 60-day break — a new benefit period begins and you get another 100 days
- There is no annual limit on the number of benefit periods you can have
- If you return to an SNF within the same benefit period (less than 60 days after discharge), coverage continues from where it left off — you do not restart at day 1
What Happens After Day 100?
After Medicare coverage ends, you have three options:
- Private pay: Pay the facility’s private-pay rate ($5,500–$8,500/month in Missouri)
- Medicaid: If you’ve spent down assets to Medicaid eligibility levels, Missouri MO HealthNet will cover long-term nursing home care. Learn about Missouri Medicaid →
- Medicare Supplement insurance (Medigap): Plans C, D, F, G, M, and N cover the days 21–100 co-pay. Some also cover a limited number of days beyond 100.
How to Appeal a Medicare Coverage Denial
If Medicare denies coverage or your SNF says Medicare is ending your coverage:
- Request a written Notice of Medicare Non-Coverage (NOMNC) — you are entitled to this
- File a fast appeal with your Quality Improvement Organization (QIO) within 2 calendar days of receiving the notice
- Coverage continues during the appeal process — you will not be billed during this time
- If the QIO upholds the denial, you can continue appealing through additional levels (Redetermination, Reconsideration, ALJ)
Many families successfully appeal early Medicare terminations, especially when the facility helps document the continued need for skilled care.
