No profession is more about reinvention than acting, but this year’s comedy supporting acting nominees are proof that Emmy voters enjoy seeing performers break out of boxes — even if those actors weren’t so sure they were in a box in the first place.

A prime example is Emmy veteran Allison Janney, who has four statuettes for her dramatic acting on NBC’s “The West Wing,” and earned her first comedy nom this year for her work as Bonnie, a recovering alcoholic single mom, on CBS’ freshman sitcom “Mom.” (She’s also nommed for her guest drama role on Showtime’s “Masters of Sex.”)

“I love comedy so much, and I’ve always been a very physical person,” she says. “It’s always been part of my repertoire. ‘Mom’ is a traditionally comic (show), but as far as I’m concerned, we could put ‘Mom’ in the drama category. We do it all.”

While Janney says she’s always looked for ways to avoid typecasting and to keep people guessing, she’s not the only actor in this year’s race that’s breaking new ground. Reinvention can happen in many ways, including traditionally dramatic thesps making a successful move to comedy (“Brooklyn Nine-Nine’s” Andre Braugher), child actors seizing the opportunity to prove that their acting chops extend into adulthood (“Big Bang Theory’s” Mayim Bialik and “Veep’s” Anna Chlumsky) and general persistence in the TV world finally paying off (“Veep’s” Tony Hale and “Modern Family’s” Julie Bowen, Ty Burrell and Jesse Tyler Ferguson). Some nominees break out in different ways. Adam Driver has gone from obscurity to stardom (and a role in the new “Star Wars” movie) thanks to “Girls,” while performers Kate McKinnon (“Saturday Night Live”) and Fred Armisen (“Portlandia”) appear on shows where they’re always doing the unexpected.

Perhaps the weightiest story of reinvention this season is five-time Emmy winner Braugher, who spent two decades skillfully playing dedicated doctors and gritty cops on dirty streets. He says he was looking for something outside his norm when Michael Schur and Dan Goor approached him about a new Fox comedy starring “Saturday Night Live” alum Andy Samberg.

“I’ve been on a lot of different kinds of shows and coming off of (ABC’s cancelled 2013 military drama) ‘Last Resort,’ I thought spiritually I needed to do something different,” Braugher says. “I felt as though (Mike and Dan) were guys who I could trust to create a world that was interesting, complex and well-grounded. The idea of playing a gay police captain is actually nothing special, but it’s got to be handled correctly otherwise it’s going to turn into a fiasco.”

Easing the transition from drama to comedy was the fact that Braugher’s character, Capt. Ray Holt, serves as the straight man to an ensemble of oddball officers.

“The straight man always reminds us of the universe that we’re a part of,” says Braugher, who, incidentally, adds that he and his son enjoy acting out Abbott and Costello’s famous “Who’s on First?” routine on occasion. “I try to hold on to that sensibility, then try to ground us in the stuff that we need to do as smart cops. I mean, someone has to remind us that Andy is out of his mind, and I’m the guy to do that.”

“Orange Is the New Black’s” Kate Mulgrew found that taking on a challenge that lies so distinctly outside of her best-known roles, such as the captain of “Star Trek: Voyager,” has been liberating.

“I’ve never questioned my own range, insofar as I found that I possess it,” says Mulgrew, who plays prison cook Red in the series. “Once you’re in that box — even though mine was a very nice box, a leading lady — it is a box nonetheless. It takes a key like this (series) to open it up, and only somebody like (series creator) Jenji (Kohan) could see it. I mean, I can just see her at her desk: ‘Kate Mulgrew? Capt. Janeway, Mary Ryan, Mrs. Columbo? Let’s give it a shot.’ ”

She immediately fell in love with her character, and says working with a younger cast has been another benefit of the series.

“It’s very invigorating to be with all those young girls,” she says. “Many of them are just starting out. They’re full of innocence, and they’re full of a marvelous energy and hope. It’s an innovative project, and they know that. We are really delighted to get into our prison cells and into our uniforms and get within those concrete beige walls.”

Janney also has been energized by the experience of shifting back and forth between Chuck Lorre’s “Mom” and “Masters of Sex.”

“I was a little nervous going from one to the other,” Janney says. “Then I realized this is exactly what I trained for in the theater. When you do theater roles, you go from one part to the other all the time, so I’m used to that. A lot of actresses in Hollywood don’t get that opportunity. If they’re not in the character actor category, you tend to get stuck in one thing.”

Nevertheless, Janney adds that she still enjoys a little drama in her comedy.

“I love having something painful behind the comedy,” she says, pointing to Lorre’s scripts that grapple with alcoholism and cancer. “That makes it richer and more relatable to people. It makes people want to root for them more.”

Braugher concludes that his first role in a sitcom has turned out to be the right decision at the right time.

“I feel lighter in spirit doing this show than I think any of the shows I might have been asked to do otherwise,” Braugher says. “This is a really refreshing break from the mayhem that characterizes the shows that I’ve done.”