Anyone familiar with Backgammon scoring?

Since the pip count represents the total number of spots that a piece must move in order to exit the board, I think that the pip count for a piece on the bar would be 25, meaning that it has to re-enter the board in your opponent's home area and go all the way around to be borne off (twenty four spaces plus one more to exit the board).

I just played a few moves with some backgammon software, to see what the effect would be to the pip count when a piece is sent to the bar. And it does appear that it placed a pip count of 25 on any piece that goes to the bar.

So it looks like 25 is your answer.