The single most expensive misunderstanding in long-term-care planning is the belief that Medicare pays for nursing homes. It does, in a narrow and time-limited sense, and it does not, in the sense that matters for custodial care lasting months or years. Families discover this distinction at precisely the wrong moment: day 101 of a stay, when the bill flips from covered to private pay at $300 to $500 per day.
The short answer
Medicare is federal health insurance primarily for people 65 and older, funded by payroll taxes. Medicaid is a joint federal-state program for low-income and low-asset individuals, funded by general revenues. They serve different populations, pay for different things, and treat nursing-home care under fundamentally different rules.
Medicare covers skilled nursing facility (SNF) stays following a qualifying 3-day inpatient hospital admission — days 1 through 20 at no cost to the patient, days 21 through 100 at a daily copay of $217.00 (2026, per CMS). The benefit requires the patient to need skilled care — services that only a licensed nurse or therapist can provide — and ends the moment skilled need stops, even if day 100 has not arrived. After day 100, Medicare pays nothing for SNF care. Period.
Medicaid covers long-term custodial care — assistance with activities of daily living (bathing, dressing, eating, transferring, toileting) in a nursing facility, for as long as the care is needed. There is no day limit. There is, instead, the eligibility wall: $2,000 (2026) in countable assets for the applicant, $157,920 (2026 federal ceiling) in protected community-spouse assets, and a monthly income below the state's income cap (typically $2,829 in 2026 under the federal-common-threshold tier).
The gap
The gap is the space between Medicare's day 101 and Medicaid's eligibility date. It is where the majority of private-pay nursing-home spending happens. A patient enters the hospital on Day 0, spends 5 days inpatient, transfers to a skilled nursing facility on Day 5, rehabs for 30 days covered fully by Medicare, rehabs for another 40 days at the Medicare days-21-100 copay, and then on Day 75 the facility determines that skilled need has resolved. Medicare coverage ends that day. Medicaid has not started because the patient still has $120,000 in savings. The family enters private pay at $10,500 per month (2026 national median) until the assets spend down to $2,000.
In a family with $150,000 in assets and no community spouse, the spend-down runs about 14 months. In a state with a $12,000 penalty divisor and a recent gift history, the lookback penalty can extend ineligibility by additional months. In a family with a community spouse retaining $157,920 in CSRA assets, the applicant's share spends down faster but the spousal share stays protected.
The size of the gap is why Medicaid planning exists as a field. Medicare will not fill it. Long-term-care insurance fills it if purchased 15 to 25 years before the claim — but policies are expensive, underwriting is tight after age 70, and penetration in the U.S. population is under 10%. Veterans' Aid and Attendance fills part of it for wartime-service veterans and surviving spouses. Everything else is private pay until Medicaid eligibility.
What doesn't work
Assuming Medicare coverage will continue indefinitely. Assuming that "Medicare supplement" (Medigap) policies cover long-term nursing-home care — they cover Medicare cost-sharing for services Medicare itself covers, which means they also stop at Day 100. Assuming that a Medicare Advantage plan's expanded benefits include long-term custodial care — they do not, with very few pilot exceptions. Assuming that a short rehabilitation stay will not turn into a permanent placement — the data suggests roughly 20% of SNF rehab admissions become long-term stays.
The planning question is not "will Medicare cover this." The planning question is "how long is the gap, and how do we fund or qualify for coverage of it." Asked early enough, the answer includes long-term-care insurance and Medicaid Asset Protection Trusts. Asked during a crisis, the answer narrows to spend-down, community-spouse allowances, and personal service contracts — still valuable, but much tighter.