The Medicare 100-Day Rule: Myth vs. Reality
"Medicare covers 100 days" is the version people remember. It's also wrong in three separate ways.
Medicare does not cover 100 days in a nursing home, flat. Coverage requires a qualifying 3-day hospital stay first. Days 1-20 are fully covered. Days 21-100 cost $217 a day in coinsurance (2026). After day 100, Medicare pays nothing at all. Three separate conditions, and the common version of this "rule" skips all three.
How many days does Medicare cover in a nursing home? Ask most people and you'll hear "100 days," stated as a flat, guaranteed benefit. It's one of the most persistent myths in Medicare, and it leaves people financially blindsided starting on day 21, not day 101, because the myth skips the part where the bill actually starts.
Myth: Medicare automatically covers 100 days in a nursing home
Reality: coverage isn't automatic at all, and it isn't uniform across those 100 days even when it applies. Two conditions have to be met before any of this coverage exists, and the 100 days themselves split into two very different cost tiers.
Condition one: the 3-day hospital rule
You generally need to have been formally admitted as a hospital inpatient for at least 3 consecutive days, not counting the day of discharge, immediately before entering the skilled nursing facility. This trips people up constantly because of a specific technicality: time spent in a hospital bed under "observation status" doesn't count toward this requirement, even overnight, even for multiple nights, unless you were formally admitted as an inpatient. Without a qualifying 3-day inpatient stay, Original Medicare generally won't cover the SNF stay at all, and some Medicare Advantage plans waive this rule, which makes it worth confirming with your specific plan.
Condition two: days 1-20 versus days 21-100 are not the same
Even once the hospital-stay condition is met, the "100 days" aren't one flat benefit. Days 1 through 20 are fully covered with no coinsurance. Starting on day 21, a daily coinsurance kicks in, $217 in 2026, for every day through day 100. That's the number the popular version of this rule leaves out entirely: the bill doesn't start on day 101, it starts on day 21, and it's a real, per-day out-of-pocket cost for the remaining 80 days if a stay runs that long.
What happens after day 100
After day 100 in a single benefit period, Original Medicare pays nothing further for that stay, regardless of medical necessity. A benefit period only resets once you've gone 60 consecutive days without inpatient hospital or skilled nursing care, so a new hospitalization within that 60-day window continues your existing day count rather than starting a fresh 100 days.
The Medigap escape hatch
If you carry a Medigap policy, this is one of the areas where it earns its premium. Most Medigap plans, including the widely held Plans G and N, cover the days 21-100 coinsurance in full, effectively eliminating this specific cost for policyholders. For anyone without Medigap facing an extended rehab or nursing stay, that $217-a-day figure across 80 possible days ($17,360 total) is exactly the exposure this myth hides.
Frequently Asked Questions
Does Medicare really cover 100 days in a nursing home?
No. Medicare covers up to 100 days per benefit period, but only the first 20 are fully covered. Days 21-100 require a $217/day coinsurance in 2026, and coverage stops completely after day 100.
What is the 3-day rule for Medicare skilled nursing facility coverage?
You generally need a formal hospital inpatient admission of at least 3 consecutive days immediately before the skilled nursing facility stay, or Original Medicare won't cover it at all. Time under "observation status" doesn't count unless you were formally admitted.
What is the Medicare SNF coinsurance for 2026?
$217 per day for days 21 through 100 of a benefit period in 2026, up from $209.50 in 2025.
Does Medigap cover the skilled nursing facility coinsurance?
Most Medigap plans, including Plans G and N, cover the days 21-100 coinsurance in full, which can eliminate this specific cost entirely for policyholders.
This article is for general educational purposes and reflects 2026 CMS figures. It is not medical or financial advice. Confirm your specific coverage with Medicare or your plan directly.