Medicare

By the Retiree Report Editorial Team · Updated 2026-06-06 · 7 min read

This article is general information, not medical advice. Talk with a licensed clinician before making any decision about your care.

Medicare’s 100-day skilled nursing rule: what counts, what cuts coverage off, and how to plan for day 21

Medicare Part A can pay for up to 100 days in a skilled nursing facility after a hospital stay — but it pays the full bill only through day 20. Starting on day 21, you owe a daily coinsurance, and in 2026 that charge is $217 a day. The 100 days are not a guarantee, either. Coverage can end well before day 100 if the facility decides you no longer need daily skilled care, and it never starts at all unless a few specific conditions are met first.

What the 100-day rule actually covers

Skilled nursing facility (SNF) care is short-term, post-hospital care. Think of the weeks after a hip replacement, a stroke, a serious infection, or a bad fall — when you still need professional nursing or physical, occupational, or speech therapy, but you no longer need to be in a hospital. Medicare calls this “extended care,” and Part A is the part of Medicare that pays for it.

According to Medicare.gov, three things have to line up before coverage begins. You need a qualifying inpatient hospital stay of at least three days in a row. You generally have to enter the SNF within 30 days of leaving the hospital. And a doctor has to certify that you need skilled care daily — either skilled nursing seven days a week or skilled therapy at least five days a week.

That word “skilled” carries a lot of weight. Help with bathing, dressing, eating, and moving around — what the system calls custodial care — does not qualify on its own, no matter how much you need it. Medicare pays when the care can only be done safely by a licensed professional. This is the single biggest reason families are surprised when coverage runs out.

Why day 21 is the day that costs you

Here is the part most people miss until the bill arrives.

The 100 days are not free.

Days 1 through 20 are fully covered by Part A after you’ve met your hospital deductible for the benefit period (that deductible is $1,736 in 2026). Then the math changes. For days 21 through 100, you pay a daily coinsurance, and the Centers for Medicare & Medicaid Services set that amount at $217.00 per day for 2026 — up from $209.50 in 2025.

Run the numbers and the stakes get real. A full stay from day 21 through day 100 — 80 days — would leave you owing $17,360 out of pocket if you have no other coverage. After day 100, Part A pays nothing for that benefit period; you’re responsible for the entire cost. This is exactly the gap that a Medigap policy is built to fill. Most Medigap plans, including the popular Plan G and Plan N, cover that day-21-through-100 coinsurance in full, which is one of the most valuable and least discussed benefits those policies carry.

What cuts your coverage off early?

You can be discharged from Medicare coverage long before day 100. The trigger is usually the facility deciding you no longer need daily skilled care — maybe therapy drops to three days a week, or your nursing needs become routine enough that an aide can handle them. When that happens, the SNF issues a notice, and Medicare’s payments stop even if you’re still in the building.

For decades, many facilities applied an unofficial “improvement standard” — the idea that if you weren’t getting measurably better, skilled care was no longer covered. That standard was wrong. A 2013 court settlement, Jimmo v. Sebelius, forced CMS to confirm in writing that coverage “does not turn on the presence or absence of a beneficiary’s potential for improvement, but rather on the beneficiary’s need for skilled care.” In plain terms: skilled care that maintains your condition, or slows a decline, can qualify just as much as care that improves it. Someone with Parkinson’s or multiple sclerosis, for example, may need skilled therapy simply to keep from getting worse — and that still counts.

So what should you do if you’re told coverage is ending and you disagree? You have the right to a fast appeal, and the discharge notice you receive explains how to file one. Don’t assume the facility’s word is final. The Jimmo settlement exists precisely because the rules were being applied too narrowly, and the appeal process is there to be used.

The three-day trap and observation status

The qualifying hospital stay rule causes more lost coverage than almost anything else, and it comes down to a single word: inpatient. Only days you spend formally admitted as an inpatient count toward the three-day requirement. Time spent in the emergency room or under “observation status” — even if you’re in a hospital bed overnight for two or three nights — does not count, according to both Medicare.gov and your State Health Insurance Assistance Program.

This catches people constantly. You can spend three nights in the hospital, feel certain you’ve met the rule, and then learn your stay was classified as observation the whole time — which means Medicare won’t pay a dime toward the SNF that follows. Hospitals are required to give you a written notice (the Medicare Outpatient Observation Notice, or MOON) when you’ve been under observation for more than 24 hours, so read anything you’re handed and ask directly: “Am I admitted as an inpatient, or am I here under observation?” It’s one of the most important questions you can ask before a discharge. Knowing your hospital discharge rights under Medicare before you need them can save you tens of thousands of dollars.

One more wrinkle worth knowing: Medicare Advantage plans often handle these rules differently. Some waive the three-day inpatient requirement, but most also require prior authorization for SNF care and can apply their own limits. If you’re on an Advantage plan, confirm the rules with your plan, not the Original Medicare handbook.

How to plan for day 21 and beyond

Start before the hospital discharge, not after. Ask the hospital case manager or social worker two things: whether your stay is being counted as inpatient, and whether the SNF you’re heading to is Medicare-certified. Both answers shape whether coverage applies at all.

Then plan for the back half of the stay. If you have a Medigap policy, check that it covers SNF coinsurance — most do, and it can erase that $217-a-day exposure entirely. If you don’t, and the stay is likely to run long, talk with the facility’s billing office early about what days 21 through 100 will cost and what happens after day 100. For care that stretches beyond what Medicare covers, the costs shift into long-term care territory, which Medicare was never designed to pay for. (That’s a separate planning question, and our look at whether long-term care insurance is still worth it walks through the tradeoffs.) None of this is a substitute for advice from a benefits counselor or your own doctor — your free local SHIP office can review your specific situation at no charge.

What to remember

Medicare’s skilled nursing benefit is generous but conditional: up to 100 days per benefit period, fully paid only through day 20, then $217 a day in 2026 from day 21 through day 100. Two things most often go wrong — a hospital stay that was observation rather than inpatient, and a coverage cutoff based on the long-debunked “improvement” myth that Jimmo overturned. Ask whether you’re admitted as an inpatient, keep every notice you’re handed, and don’t accept a coverage denial without considering an appeal.