The 40th District includes 15 communities in Bergen, Essex, Morris, and Passaic counties: Allendale, Cedar Grove, Franklin Lakes, Ho-Ho-Kus, Little Falls, Midland Park, Pequannock, Pompton Lakes, Ridgewood, Riverdale, Totowa, Waldwick, Wayne, Woodland Park, and Wyckoff.

Voter registration is more than one-quarter Democratic and nearly one-third Republican, with most other district voters unaffiliated.

Both Republican incumbents are seeking re-election. They are Assemblymen Kevin J. Rooney and Christopher P. DePhillips, both of Wyckoff.

The Democratic team comprises Michael A. Sedon of Ridgewood and Maria Martini Cordonnier of Upper Montclair.