Techniques for supporting handoff of a terminal between base stations of different protocol revisions (P_REVs) in a CDMA system. The terminal is handed off from a first base station (with a first P_REV) to a second base station (with a second P_REV) while it is in an active (data or voice) call with the first base station. The second P_REV is later than the first P_REV. The active call may be maintained between the terminal and second base station using a first service configuration previously established via the first base station for the active call. A second service configuration may be established via the second base station for the active call. This may be achieved by (1) querying the terminal, (2) assignment by the second base station, or (3) initiation by the terminal. The active call may then be maintained using the second service configuration if available.