 On April 19, 1998, 660 became mandatory for all calls in the affected area.In 2000, the Missouri PSC announced plans to add 975 as an overlay to the 816 area code; however, with the subsequent implementation of number pooling, the commission determined there was no immediate need for additional phone numbers and postponed the May 5, 2002 implementation date indefinitely.Despite Kansas City's continued growth and the fact that the metropolitan area is a single LATA, the Kansas City area will not need another area code until 2026.