Act 819 (the Act) of the 2006 Regular Session of the Louisiana Legislature amended R.S. 37:1306-1310 requires the Department of Health to publish primary service area descriptions and provide annual updates to encourage innovative collaboration between and among rural hospitals and physicians in delivery of health care services in rural areas.

The Act defines primary service area of a rural hospital as the smaller of either a radius of 25 miles from the rural hospital main campus or the number of postal zip codes, commencing with the rural hospital's zip code, in which 75 percent of a rural hospital's patients reside, as determined by using data derived from the hospital's most recent 12 month Medicare cost reporting period.

The 25 miles radius of each rural hospital has been identified by geocoding the zip code of each rural hospital and the 25 mile radius surrounding each of these hospitals.