Does the Medicare 3-Day Rule Increase Length of Stay?

Medicare will only cover a stay in a skilled nursing facility (SNF) after TKA if the patient stays for at least 3 days at the inpatient hospital. The 3-day stay rule was instituted in 1965, to prevent over utilization of Medicare. We retrospectively reviewed 800 consecutive TKA, identifying patients that were discharged to rehab after surgery. 322 patients were discharged to SNF after surgery (209 Medicare, 113 private insurances). The LOS was 2.3 days for privately insured patients and 3.02 for Medicare recipients (P<0.05). No difference was found with regard to age, BMI, and ASA score. The Medicare 3-day rule independently increased the LOS in patients who required inpatient rehab, leading to increased cost. We suggest that this rule must be revised.