As of 2018-19 season, the 31 NHL teams are arranged into two conferences with two divisions each. The Eastern Conference includes the Atlantic and Metropolitan divisions, and the Western Conference is divided into the Central and Pacific divisions.

Although there has been much shifting of teams over the years, the NHL has arranged itself as two conferences containing multiple divisions since 1974.

In the current configuration, the Atlantic Division consists of the Boston Bruins, Buffalo Sabres, Toronto Maple Leafs, Montreal Canadians, Ottawa Senators, Tampa Bay Lightning, Detroit Red Wings, and Florida Panthers. The Metropolitan Division includes the Carolina Hurricanes, New York Islanders, Washington Capitals, New Jersey Devils, Philadelphia Flyers, Columbus Blue Jackets, Pittsburgh Penguins, and New York Rangers.

The Central Division is composed of the Chicago Blackhawks, Dallas Stars, Colorado Avalanche, Nashville Predators, Winnipeg Jets, Minnesota Wild, and St. Louis Blues. The Pacific Division is made up of the Anaheim Ducks, Los Angeles Kings, Calgary Flames, Vancouver Canucks, San Jose Sharks, Las Vegas Golden Knights, Edmonton Oilers, and Arizona Coyotes.

Here's a look at the divisional and conference setups employed since the NHL was founded in 1917:

1917-1926:

No divisions. Number of league teams ranges from three in 1918-19 to seven in 1925-26.

Montreal Canadiens

Toronto Arenas/Toronto St. Pats

Ottawa Senators

Montreal Maroons (starting in 1924)

Boston Bruins (starting in 1924)

New York Americans (starting in 1925)

Hamilton Tigers (1920-25)

Pittsburgh Pirates (starting in 1925)

Montreal Wanderers (played six games in 1917-18 before withdrawing after their rink burned down)

1926-1938:

Canadian Division, with four or five teams.

Montreal Canadiens

Toronto St. Pats/Toronto Maple Leafs

Montreal Maroons

New York Americans

Ottawa Senators (missed 1931-32 season; returned from 1932-1934 before withdrawing for good)

St. Louis Eagles (1934-35)

Toronto St. Pats/Toronto Maple Leafs Montreal Maroons New York Americans Ottawa Senators (missed 1931-32 season; returned from 1932-1934 before withdrawing for good) St. Louis Eagles (1934-35) American Division, with four or five teams.

New York Rangers (starting in 1926)

Boston Bruins

Chicago Blackhawks (starting in 1926)

Pittsburgh Pirates (until 1930)

Detroit Cougars/Detroit Falcons/Detroit Red Wings (starting in 1926)

Philadelphia Quakers (1930-31)

1938-1942:

Seven teams, no divisions.

Boston Bruins

New York Rangers

Toronto Maple Leafs

New York Americans/Brooklyn Americans

Detroit Red Wings

Montreal Canadiens

Chicago Blackhawks

1942-1967:

Six teams, no divisions.

Boston Bruins

New York Rangers

Toronto Maple Leafs

Detroit Red Wings

Montreal Canadiens

Chicago Blackhawks

1967-1974:

East Division and West Division. Each division begins with six teams in 1967-68, expanding to eight teams each by 1973-74.

Boston Bruins

New York Rangers

Toronto Maple Leafs

Detroit Red Wings

Montreal Canadiens

Chicago Blackhawks

Philadelphia Flyers

Los Angeles Kings

St. Louis Blues

Minnesota North Stars

Pittsburgh Penguins

Oakland Seals/California Seals

Buffalo Sabres (starting in 1970)

Vancouver Canucks (starting in 1970)

New York Islanders (starting in 1972)

Atlanta Flames (starting in 1972)

1974-1993:

Prince of Wales Conference, with Adams and Patrick Divisions.

Clarence Campbell Conference, with Norris and Smythe Divisions.

League expands from 18 teams in 1974-75 to 24 teams in 1992-93.

Boston Bruins

New York Rangers

Toronto Maple Leafs

Detroit Red Wings

Montreal Canadiens

Chicago Blackhawks

Philadelphia Flyers

Los Angeles Kings

St. Louis Blues

Minnesota North Stars

Pittsburgh Penguins

California Golden Seals (until 1976)

Buffalo Sabres (starting in 1970)

Vancouver Canucks (starting in 1970)

New York Islanders (starting in 1972)

Atlanta Flames (until 1980)

Washington Capitals (starting in 1974)

Kansas City Scouts (1974-1976)

Colorado Rockies (1976-1982)

Cleveland Barons (1976-1978)

New Jersey Devils (starting in 1982)

Calgary Flames (starting in 1980)

Quebec Nordiques (starting in 1979)

Hartford Whalers (starting in 1979)

Winnipeg Jets (starting in 1979)

Edmonton Oilers (starting in 1979)

San Jose Sharks (starting in 1991)

Tampa Bay Lightning (starting in 1992)

Ottawa Senators (starting in 1992)

1993-2013:

Eastern Conference, with Atlantic, Northeast, and Southeast Divisions.

Western Conference, with Central, Western, and Pacific Divisions.

League expands to 30 teams.

Boston Bruins

New York Rangers

Toronto Maple Leafs

Detroit Red Wings

Montreal Canadiens

Chicago Blackhawks

Philadelphia Flyers

Los Angeles Kings

St. Louis Blues

Pittsburgh Penguins

Buffalo Sabres

Vancouver Canucks

New York Islanders

Washington Capitals

New Jersey Devils

Calgary Flames

Quebec Nordiques (until 1995)

Hartford Whalers (until 1997)

Winnipeg Jets (until 1996)

Winnipeg Jets (starting in 2011)

Edmonton Oilers

San Jose Sharks

Tampa Bay Lightning

Ottawa Senators

Dallas Stars (starting in 1993)

Florida Panthers (starting in 1993)

Anaheim Mighty Ducks/Anaheim Ducks (starting in 1993)

Colorado Avalanche (starting in 1995)

Phoenix Coyotes (starting in 1996)

Carolina Hurricanes (starting in 1997)

Nashville Predators (starting in 1998)

Atlanta Thrashers (1999-2011)

Columbus Blue Jackets (starting in 2000)

Minnesota Wild (starting in 2000)

2012-2019: