In Sorry!, do you have to move past safety zone or forfeit turn?
You forfeit your turn.

From the rules (3 separate places): 


  
  You must bring all four of your pawns into HOME by 
  exact count!
  If at any time you cannot move, you forfeit your turn.
  When moving along 
  the outside track, you may not move your pawn 
  forward beyond your own SAFETY ZONE entry.
  


Also a note under the rules for the 11 card:


  
  You may forfeit your move if you do not wish to change 
  places and it is impossible to go forward 11 spaces.