The Balanced Budget Act of 1997 included the Medicare Rural Hospital Flexibility Program (FLEX), which was intended to support rural health care.  The FLEX program allowed licensed acute-care rural hospitals nationwide to apply to become CAHs if they met specific criteria. The advantages to CAH status include access to Flex Program grant money, cost-based reimbursement, and access to capital improvement costs. For some hospitals, CAH designation has made the difference between closing the doors and continuing to serve the community. These hospitals have to meet certain criteria, including being located in a rural area, more than 35 miles from another hospital, at least 15 miles from another hospital if in mountainous terrain or over secondary roads, or state certified as a necessary provider of health care services to area residents. CAHs must provide 24-hour emergency services, with medical staff either on site or on call and available on site within 30 minutes. If a physician is not on site 24/7, the facility must post public notice of this, stating that a registered nurse would render treatment until the physician or midlevel provider arrives. Additional requirements include maintaining a mean annual length of stay of 96 hours or less, having a maximum of 25 beds, and having patient referral and transfer agreements with other acute-care hospitals in place.