Our patrol captain does this for retiring deputies that don't already have a LTC...it is no cost while you are still active LEO. I recently did it myself.
Sometimes state specific. In Nebraska (as of 5+ years ago), someone who held a CHL could not use the existing "reasonable", Jim Crow era legal provision, which technically was the authority LE had for being armed off duty. Ergo, cops did not obtain CHL's, as they limited places one could carry. This is also the reason that the state legislature removed a requirement for CHL instructors to be CHL holders, as coppers would not be eligible to be instructors without being subject to said restrictions.