In Arizona Health Care Cost Containment System Administration v. Carondelet Health System, 188 Ariz. 266, 935 P.2d 844 (App. 1996), the Court struck an Arizona Health Care Cost Containment System ("AHCCCS") regulation because it took away coverage that the legislature had provided. At issue in Carondelet was the definition of "emergency medical services." Id. at 269, 935 P.2d at 847. The legislature defined the term as "'immediate medical care . . . in order to preserve the person's health, life or limb.'" Id. at 270, 935 P.2d at 848 (quoting A.R.S. 41-1831(7)). AHCCCS, however, adopted a "sudden onset" rule which had the effect of precluding those who needed emergency medical services but "who have suffered symptoms for a period of time before their conditions became critical." Id. The Court struck down the "sudden onset" rule because its effect was "to eliminate emergency medical coverage for an entire group of patients who would otherwise be covered." Id.