You can change your pension decision post Apr 06 if and only if the decision you made prior to that date was based on incorrect information. I know, I originally elected to go with AFPS 05 but when it was discovered that information provided to me by my own desk officer was incorrrect, I approached the pensions office who allowed me to revert to AFPS 75 in Sep 06. Desk officer had a lot to answer for......yeah, right! Not even a sorry to all those he gave false hopes to or who have made decisions based on his wrong writings. The thing now is that now I am on AFPS 75, I will definitely not remain until my 55th birthday AFPS 05 would have kept me. A retention dis-incentive.