Skilled Nursing Facility (SNF)

Key facts

Legal basis

Section 1819 of the Social Security Act; Section 1919 for Medicaid nursing facilities

Federal standards

Long-term care facility requirements, 42 CFR Part 483, Subpart B

Medicare coverage

Up to 100 days per benefit period after a qualifying hospital stay

Medicare payment

SNF PPS, Patient Driven Payment Model (PDPM) since October 2019

Assessment tool

Minimum Data Set (MDS)

What is a skilled nursing facility?

SNFs care for patients who no longer need a hospital but still need skilled services every day, such as wound care, intravenous therapy, or physical, occupational and speech therapy after a stroke or hip fracture. Skilled means the care must be performed or supervised by licensed nurses or therapists.

Most buildings people call nursing homes are dually certified. The same facility bills Medicare as an SNF for short post-acute stays and Medicaid as a nursing facility for residents who need long-term custodial care. Both groups are covered by the federal requirements in 42 CFR Part 483, and state survey agencies inspect facilities against them.

How Medicare SNF coverage works

Medicare Part A covers SNF care only under specific conditions:

• The patient generally needs a qualifying inpatient hospital stay of at least three consecutive days. Time in observation status does not count, although Medicare Advantage plans and some CMS payment models waive the rule.
• Part A covers up to 100 days per benefit period. Days 1 through 20 have no coinsurance, and days 21 through 100 carry a daily coinsurance amount.
• Coverage continues only while the patient needs and receives daily skilled care. Custodial care alone is not covered.
• Under the Patient Driven Payment Model, daily rates depend on patient characteristics recorded in the MDS rather than on minutes of therapy provided.

Why SNF data matters

SNFs are a major post-acute cost center and a heavily reported facility type:

• Hospitals, accountable care organizations and Medicare Advantage plans build preferred SNF networks to control post-acute spending and readmissions.
• Care Compare publishes a five-star rating for nursing homes based on health inspections, staffing and quality measures, keyed to the facility's CMS Certification Number.
• CMS publishes nursing home ownership data and daily staffing data from Payroll-Based Journal submissions, which analysts use to study chains and private equity ownership.
• Long-term care pharmacies, wound care companies and therapy providers size markets by SNF beds and Medicare days.