Five Board of Education members approved Mr. Pliego's appointment Tuesday evening.
One board member, David Lawson, abstained from the vote.
The appointment date began July 1.
Mr. Pliego's salary will be $104,657. He had been serving as interim athletic director at the high school since Dec. 1, when he returned to the district from an athletic director position in Brewster, N.Y.
Keith Lipinsky, an NMHS physical education teacher, was appointed Tuesday as head teacher in the physical education department for the 2012-13 school year.
Mr. Lipinsky had served as substitute athletic director from mid-September to Dec. 1 following the unexpected resignation of Ted Oczkowski.
"I'm delighted," Mr. Pliego said Tuesday of his appointment. "This has always been home. Brewster was a lot of good times, lots of good people and lots of learning. But when the interim athletic director's position opened up in New Milford, I had to come back."
This is Mr. Pliego's second tenure of employment with New Milford schools.
He came to New Milford in 1995 as an athletic trainer at the high school. From 2000 to 2003, he was the assistant athletic director, and then until the end of the 2006-07 school year, he was the high school's athletic director.
"I plan to give the students more of a voice in the athletic program," Mr. Pliego said of his plans. "I'm a teacher at heart and I'd like to get more into what the students want to do, what they want to see in the program."
Mr. Pliego noted the high quality of the coaches in the program and said he plans to draw on their thoughts, as well, about program improvements.
"I want everyone to have the opportunity to play," he said. "It's important to be part of something. Being part of a team, even if you're not a star player, teaches you so much."
"It's important to give kids the opportunity to challenge themselves, whether in sports, in the band, or in the arts," Mr. Pliego added.
Mr. Pliego said, while his appointment as athletic director came late in the appointment calendar for the school year, he had " a lot of good support through the process from the principal (Greg Shugrue) and Ella Mae (Baldelli, the schools' personnel director) and JeanAnn (Paddyfote, the superintendent of schools)."
Board of Education chairwoman Wendy Faulenbach wished Mr. Pliego luck in his new position.
"I'm excited about his passion for the district and the students," Mrs. Faulenbach said. "I'm looking forward to see how he integrates students' academic and athletic performances."
"Lance puts the students first," said board member Danielle Shook. "He sees a student-athlete in a child. He holds the academic aspect of a student's development as being equally important as their athletic development. That's important to me as a teacher myself."
Mr. Pliego graduated from New Fairfield High School.
He holds degrees from Central Connecticut State University and resides in New Milford with his wife, Nicole, and their two sons, Luke, 10, and Ryan, 8.