Two medical centers in Maricopa County plan to seek trauma designations from the Arizona Department of Health Services’ emergency medical bureau.

Chandler Regional Medical Center plans to open a Level I trauma center. Its sister hospital, Mercy Gilbert Medical Center, is planning for a Level III facility.

For Chandler Regional, a Level I designation would mean it could treat the most life-threatening injuries. Medical and surgical specialists would be on hand around the clock.

Currently, there are six Level I trauma centers in Phoenix and one in Scottsdale.

Elected leaders and representatives from the medical community have been advocating for a Level I trauma center in the southeast part of the Valley.

Medical center officials cited a 2012 state report that showed only 42 percent of critically injured patients in Maricopa County arrived at a Level I center within an hour of being injured.