The tailwheel endorsement does not require a minimum number of flight hours to obtain, and can possibly be accomplished efficiently and safely within a few hours of flight training. CFR 61.31(i) does, however, require at least certain maneuvers and procedures be performed:
Normal and crosswind takeoffs and landings.
Wheel landings (landing on the main gear while holding the tail off the ground — check for manufacturer recommendations against such landings).
Go-around procedures.
Your instructor might require additional maneuvers or procedures be performed in order for you to demonstrate proficiency in a tailwheel airplane. These maneuvers might include stalls, steep turns, emergency maneuvers and procedures, etc.
Once your instructor has determined that you’re proficient in the operation of a tailwheel airplane, he or she will endorse your logbook. AC 61-65 provides guidance on various types of endorsements, so your instructor might choose to endorse your logbook with the following:
I certify that (First name, MI, Last name), (pilot certificate), (certificate number), has received the required training of CFR 61.31(i) in a (make and model of tailwheel airplane). I have determined that he/she is proficient in the operation of a tailwheel airplane.
S/S [date] J.J. Jones 987654321CFI Exp. 12-31-19
The training and endorsement required to operate a tailwheel airplane is not required if you logged pilot-in-command time in a tailwheel airplane before April 15, 1991.