An article in Forbes Magazine indicates that in 2016, every state made at least one positive change to laws or regulations affecting physician assistants. Similar to nurse practitioners and allied health professionals in general, barriers to PAs are falling for a variety of reasons including a doctor shortage and general comfort U.S. patients have with being treated by someone other than a physician.
The article can be obtained at https://www.forbes.com/sites/brucejapsen/2017/09/08/states-lift-more-hurdles-to-physician-assistants/#7fd00d8422ef.