A pilot study was undertaken to examine the impact of Medicare's 3-day rule on length of stay (LOS). One hundred consecutive patients who underwent primary total joint arthroplasty and were discharged to extended care facilities were retrospectively reviewed. Based on readiness for discharge criteria, delaying discharge until the third postoperative day increased LOS by 1.1 days (P<0.001). 60.6% of patients were ready for discharge by the second postoperative day, none of whom required re-admission within 30 days of discharge. There were no rehabilitation gains by staying an additional hospital day beyond readiness for discharge (P=0.092). This pilot study calls into question the value of Medicare's 3-day rule and demonstrates the feasibility and need for further research to address this seemingly antiquated policy.