Men's Division I is a set of schools and conferences that sponsor men's hockey and abide by the National Collegiate Athletic Association's rules and regulations for Division I ice hockey. There are currently six conferences that sponsor Division I hockey:
- Atlantic Hockey
- Big Ten
- ECAC Hockey
- Hockey East
- National Collegiate Hockey Conference
- Western Collegiate Hockey Association
- The WCHA is now likely to disband as a men's conference after the 2020–21 season. In June 2019, seven of its 10 men's members at the time announced they would withdraw from the league after that season. These schools then announced in February 2020 that they would start play in a revived Central Collegiate Hockey Association in the 2021–22 season. Another men's member, Alabama–Huntsville, had filed papers to leave, and briefly folded its hockey program in May 2020 due to fallout from the COVID-19 pandemic before reinstating it a week later. One of the remaining members, Alaska–Anchorage, still later announced it would drop men's ice hockey after the 2020–21 season.
These six conferences represent all but two of the 61 teams that compete at the Division I level in men's hockey. The Arizona State Sun Devils and LIU Sharks, the latter of which is playing its first varsity season in 2020–21, are Division I Independents. Both are playing the 2020–21 season in scheduling agreements with existing D-I conferences—Arizona State with the Big Ten and LIU with Atlantic Hockey. Division I represents the highest possible level of investment in hockey, and also the highest level of competition. If a school is a Division I institution, they must compete at the Division I level in all sports. However, several Division II and Division III schools choose to "play up" to Division I hockey, with the mechanics differing between D-II and D-III.
All NCAA members below D-I are allowed to "play up" in any sport that does not have a national championship for the school's own division. Since the NCAA abolished the Division II men's hockey championship after its 1998 edition, D-II schools have been allowed to compete as D-I hockey members under D-I rules. The Northeast-10 Conference, a D-II all-sports league, chose to continue playing under D-II rules; currently, six of its eight men's hockey schools play under D-II regulations, while the other two play in D-I as part of Atlantic Hockey. All other D-II men's hockey schools compete in D-I.
Since Division III has a men's championship, only D-III members covered by an NCAA grandfather clause are allowed to continue playing as D-I schools. A separate grandfather clause allows a subset of these schools to award hockey scholarships, a practice otherwise prohibited in D-III.