Refers to the one-third of the US electric grid and electricity markets where vertically integrated utilities own and operate all of the generators, transmission lines, and distribution networks. Regulated markets dominate most of the southeastern, northwestern and much of the western US (excluding California).

This is in contrast to deregulated electricity markets where the grid is managed and monitored by regional transmission organizations and independent system operators.

For more information, see Country Q&A, Electricity Regulation in the United States: Overview.