In a deregulated electricity market, which represents about two-thirds of the US electricity market, market participants other than utilities own power plants and transmission lines. This enables other companies (independent power producers and other generators) to generate and deliver electricity to the electric grid. In these markets, transmission assets are operated and maintained by regional transmission organizations and independent system operators. These entities also manage access to the grid.

This is in contrast to regulated electricity markets where vertically integrated utilities generate power, own the transmission lines, and deliver the electricity to retail customers.

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