A new area code will be activated next year in central Florida counties Orange, Osceola, Seminole and parts of Lake and Volusia, all currently using area codes 407 and 321. The soon to enter service area code 689 was initially planned for activation in 2002, but its implementation was then postponed. 10 digit dialing has been mandatory in the area since the introduction of area code 321 back in 1999, so there will be no change in the way calls are being dialed.
The new NPA 689 will enter service on June 4, 2019.
See official Nanpa announcement and NPA maps (PDF document)