We are in the middle of a transition period from regulated to largely competitive electricity markets. PSC approved costs were built into the rate base. Transmission and distribution were part of the fully regulated monopoly. Approved costs were built into rate base. Transmission access controlled by owners of the lines.
Some states have retail competition, i.e., customers choose their electricity suppliers.
Deregulation of generation in some states. Transmission and distribution remain regulated, but access is open to wholesale transactions. Open access for retail sales in some states. Distribution regulated, but in no way impeding open competition. Residential, commercial, and industrial customers, both in and out of the state, will be able to obtain power from the most efficient sources.