Critical Access Hospital (CAH)
A critical access hospital (CAH) is a small rural hospital that Medicare certifies under 42 CFR Part 485 Subpart F. It keeps no more than 25 inpatient beds, holds its annual average acute stay to 96 hours, offers emergency care around the clock and sits far enough from other hospitals. Medicare pays it on a reasonable cost basis.
Key takeaways
- A Medicare designation for small rural hospitals, set in 42 CFR Part 485 Subpart F
- More than a 35-mile drive from another hospital, or 15 miles on mountainous or secondary roads
- No more than 25 inpatient beds and an annual average acute stay of 96 hours or less
- Emergency services 24 hours a day, with a qualified practitioner on call
- Inpatient services paid on reasonable cost under 42 CFR 413.70, settled through the cost report
What Critical Access Hospital means
The designation starts with the state. A state that runs a Medicare rural hospital flexibility program, known as the Flex Program, designates the facility. The state survey agency or CMS then surveys it, and CMS certifies it once it meets the conditions of participation in Subpart F.
The rules matter to software because a CAH has to keep proving them, not prove them once. Bed counts, length of stay, emergency coverage and the cost report all come from data held in the EHR, the bed board and the finance system. When those systems disagree, the hospital finds out during a survey or a cost report review.
Agnotic Technologies builds reporting and integration work for rural hospitals so these numbers come from one source. Swing-bed tracking and rural telehealth are covered on our rural healthcare technology page.
Why does cost-based payment change the software?
Because payment follows reasonable cost, the cost report is a revenue document, not only a filing. Costs have to land in the right departments and on the right days, including the split between acute inpatient days and swing-bed days.
That puts a premium on clean statistics: patient days by type, beds in service by day and time records for staff shared across departments. Software that captures these at the source saves the finance team from rebuilding them in spreadsheets at year end.
Which rules define a critical access hospital, and what proves them?
| Rule | Federal citation | Record that proves it |
|---|---|---|
| Located in a rural area, or treated as rural | 42 CFR 485.610(b) | Address and geographic classification on file with the state and CMS |
| More than a 35-mile drive on primary roads from a hospital or another CAH (15 miles in mountainous terrain or where only secondary roads exist), or a state necessary provider certification from before January 1, 2006 | 42 CFR 485.610(c) | Driving distance analysis, or the state's necessary provider certification |
| No more than 25 inpatient beds, used for inpatient or swing-bed care | 42 CFR 485.620(a) | Daily bed census showing each bed's use |
| Annual average acute inpatient stay of 96 hours or less | 42 CFR 485.620(b) | Admission and discharge times for every acute inpatient stay |
| Emergency services available 24 hours a day | 42 CFR 485.618(a) | Emergency department staffing schedule |
| Qualified practitioner on call and on site within 30 minutes (60 minutes where the frontier or remote area conditions are met) | 42 CFR 485.618(d) | On-call roster and a log of response times |
| Inpatient services paid on reasonable cost | 42 CFR 413.70 | Medicare cost report with department costs and patient day statistics |
Facts and primary sources
A CAH maintains no more than 25 inpatient beds, which may be used for inpatient or swing-bed services, and its acute inpatient care must not exceed an annual average of 96 hours per patient.
Source: eCFR, 42 CFR 485.620CAH emergency services must be available 24 hours a day, with a doctor, physician assistant, nurse practitioner or clinical nurse specialist trained in emergency care on call and on site within 30 minutes in most areas.
Source: eCFR, 42 CFR 485.618A state can designate a CAH only if it has established a Medicare rural hospital flexibility program, and CMS certifies the facility after a survey finds it meets the conditions of participation.
Source: eCFR, 42 CFR 485.606Medicare pays for CAH inpatient services based on the hospital's reasonable costs, determined under the cost reimbursement principles in 42 CFR Part 413.
Source: eCFR, 42 CFR 413.70
Explore this on Agnotic
Where Critical Access Hospital shows up in how we build.