The Missouri Public Service Commission has modified the list of exchanges that can keep the 314 area code.

Residents of Washington, Warrenton, St. Clair, Jonesburg, High Hill, Holstein and Marthasville still will be reached by dialing 314. Those residents originally were slated for the 573 area that goes into effect Jan. 1.

The PSC modified its decision after a recommendation by a technical committee created by the commission to review the 314-573 area code boundaries. The technical committee recommended adding the exchanges to the 314 area code because of "the growth of the St. Louis metropolitan area into these communities and their contribution to the economic health of the metropolitan area."

The 573 area code can be dialed Jan. 1, but calls using the 314 area code will go through until July 1.