A critical access hospital (CAH) is a small rural hospital that has received a special designation from the Centers for Medicare & Medicaid Services (CMS). The designation exists to keep emergency and basic inpatient care available in places where the nearest larger hospital is a long drive away. In exchange for meeting strict size and location rules, a critical access hospital is paid by Medicare based on its reasonable costs rather than fixed rates.
If you live in or travel through rural America, there is a good chance the closest emergency department belongs to a critical access hospital. In an emergency, call 911 or go to the nearest emergency department.
Where the designation comes from
Congress created the critical access hospital program through the Balanced Budget Act of 1997, as part of the Medicare Rural Hospital Flexibility Program. Many small rural hospitals were closing in the 1980s and 1990s because standard Medicare payments did not cover the cost of running a low-volume hospital. The CAH model was designed to make those hospitals financially viable while keeping them focused on emergency care, short stays and stabilizing patients who need to be transferred.
The designation is granted by CMS after a state recommends the hospital, and the hospital must keep meeting the Medicare Conditions of Participation for critical access hospitals.
The main requirements
| Requirement | Rule |
|---|---|
| Inpatient beds | No more than 25 beds for acute inpatient or swing-bed care |
| Length of stay | Annual average of 96 hours or less per acute inpatient |
| Location | Rural, and generally more than 35 miles from another hospital (15 miles in mountainous terrain or areas with only secondary roads) |
| Emergency care | Emergency services available 24 hours a day, 7 days a week |
| Medicare payment | Paid on a reasonable cost basis for most inpatient and outpatient services |
Some hospitals that do not meet the distance rule kept their status because their state certified them as a "necessary provider" before that option ended in 2006.
A critical access hospital may also run a separate psychiatric unit or rehabilitation unit of up to 10 beds each. These units do not count toward the 25-bed limit.
What care you can expect
A critical access hospital is not a scaled-down version of a big-city medical center. It is built around a specific job:
- Emergency care around the clock, with a doctor, nurse practitioner, physician assistant or clinical nurse specialist available on call
- Short inpatient stays for conditions such as pneumonia, dehydration, heart failure flare-ups or recovery after common procedures
- Stabilization and transfer for patients who need specialized care, such as a heart catheterization, major trauma surgery or a neonatal intensive care unit
- Outpatient services including lab work, imaging, infusions and often rural health clinics
- Swing beds, which let a bed switch from acute care to skilled nursing level care so a patient can recover close to home
Many critical access hospitals also deliver babies, perform general surgery and offer telehealth links to specialists. What is available varies widely, so if you are planning care rather than facing an emergency, call ahead.
Why the 96-hour rule matters for patients
The 96-hour limit is an annual average, not a hard cap on each patient. A patient can stay longer if needed. But the rule shapes how these hospitals work: they are designed to treat and discharge, or to stabilize and transfer, rather than to manage long and complex hospitalizations. If your relative is moved from a critical access hospital to a larger regional hospital, that is usually the system working as intended.
Critical access hospitals and quality ratings
Critical access hospitals can report quality data to CMS, but many have too few cases to receive an Overall Hospital Quality Star Rating on Medicare.gov Care Compare. A missing star rating does not mean poor quality. It usually means the hospital does not have enough reported measures to calculate a score. Read How CMS Star Ratings Work for more on how ratings are calculated.
Critical access hospitals and rural emergency hospitals
Since January 1, 2023, a critical access hospital can choose to convert to a rural emergency hospital (REH). An REH keeps its emergency department open around the clock and provides outpatient services, but it stops routine inpatient care. Some struggling rural hospitals have converted instead of closing entirely. Browse rural emergency hospitals to see where these facilities are.
How billing works for patients
Cost-based reimbursement is between the hospital and Medicare. As a patient, you still pay deductibles and coinsurance. One difference to know about: for outpatient services at a critical access hospital, Medicare coinsurance is calculated on the hospital's charges rather than on a fixed Medicare rate, which can make your share higher than at another hospital. If you have questions about a bill, see How to Read a Hospital Bill and Hospital Financial Assistance.
Finding a critical access hospital
Use our list of critical access hospitals to browse by state, or hospitals near me to see what is closest to your location. For a broader overview of hospital categories, read Types of Hospitals.