All full-members of Division I in good standing are technically eligible. Programs that are making the transition to Division I from lower levels are often prohibited from postseason appearances for a specified period. Some NCAA penalties for program infractions also prohibit postseason appearances
A common misconception is only teams with records of .500 or better can receive an invitation. However, the tournament charter provides for no such requirement. It only asks that the participants come from a pool of "the 54 best teams" available.
There are no requirements, limitations or preferences when it comes to conference affiliation. The only conference stipulation is that a regular-season conference champion that is not selected to the NCAA tournament will receive an automatic berth in the NIT.
The NIT was played in New York from start to finish for decades. However, the tournament is played at the home basketball courts of its participants for the first three rounds. The semifinals and final remain held in New York.