Martin Brodeur made 22 saves for his 119th career shutout to lead the Devils (45-28-6) past the Carolina Hurricanes 5-0 and back into the play-offs after New Jersey failed to qualify last season.
"I didn't think it was going to bother me that much last year, but I was like, 'Wow, I'm really missing this atmosphere," Brodeur said.
"This year, it was an important thing for me to go out and try to get in the playoffs, to get back at it."
New Jersey join the New York Rangers, Boston Bruins, Pittsburgh Penguins and Philadelphia Flyers in having secured play-off positions in the Eastern Conference.
"It's step one," New Jersey coach Peter DeBoer said. "Now that we're in, you obviously want to make some noise. That's where we go from here."
Chicago (44-26-9) rebounded from squandering a four-goal lead to edge the Nashville Predators 5-4 and qualify for the postseason for the fourth consecutive season.
"I think it's great. This time, we don't have to wait for someone else to do it for us," said Chicago right wing Marian Hossa, referring to last season when the Blackhawks squeezed into the playoffs.
"We did it for ourselves. It's a huge win on Nashville ice."
Chicago join the St. Louis Blues, Vancouver Canucks, Detroit Red Wings and Predators in the Western Conference play-off picture.
There are three play-off positions still available in each conference with one week remaining in the season.
The Blackhawks' win over Nashville also handed the Blues their first Central Division title since 2000 despite their 5-2 defeat at the hands of the Columbus Blue Jackets.
The defending Stanley Cup champion Bruins clinched the Northeast Division with a 6-3 win over the New York Islanders.