Milo (Hader) writes a suicide note and cuts his wrists. Meanwhile, Maggie (Wiig) is in her bathroom preparing to swallow a handful of pills, but is interrupted by a call from a hospital informing her that her brother – whom she hasn't seen in 10 years – has unsuccessfully attempted suicide. Maggie visits Milo in the hospital in Los Angeles, and suggests that he come to stay with her in their hometown of Nyack, New York for a while; he reluctantly agrees. Milo meets Maggie's gregarious husband Lance (Luke Wilson), who states that he and Maggie are trying to have a baby, which surprises Milo, as Maggie never wanted children. Milo reacquaints himself with the town, and observes Rich (Burrell), a middle-aged man working in a bookstore. Meanwhile, Maggie is taking scuba lessons, and having sex with the instructor, Billy (Holbrook).
At Milo's invitation, their mother (Gleason) makes a surprise visit.
Maggie asks Milo if she'd be a good mother, and Milo honestly replies that she'd be overprotective and uptight, which upsets her; he later apologizes, joking that the reason he said that was his concern about her "morbid obesity." Maggie later confesses to Milo that she's been taking birth control pills, both to avoid having a child with Lance and because she's been sleeping with the instructors of all the classes she's been taking. She worries that she's not worthy to be married to Lance, but Milo reassures her.
Milo meets with Rich, who was his high school English teacher. They had a sexual relationship when Milo was 15. Rich now has a 16-year-old son, and is dating a woman. Milo lies about his career, claiming to have an acting agent in Los Angeles, when he really just waits tables at a tourist restaurant. Milo and Rich spend the night together. Later Milo shows up at Rich's house while his son is there, infuriating him with the danger of his past being exposed. Milo gets drunk, and throws away a trinket that Rich had given him in high school, which he still carried as a keepsake.
Milo tells Maggie about a boy that had once bullied him, who – their father had assured him – would reach his peak in high school and have a miserable adult life. But it turned out that the bully had a successful happy life, and it was Milo who had peaked in high school. Maggie asks for reassurance that he won't kill himself, and he promises to try not to. Maggie and Milo spend Halloween together, and reminisce about their father's death. Milo leaves his phone behind when he goes to the bathroom, and Maggie sees an incoming call from Rich. She is upset with Milo for resuming contact with Rich. Maggie had exposed their sexual relationship, ending Rich's teaching career.
Lance confides to Milo that he is concerned that he may be infertile. Milo mentions that Maggie used to hide cigarettes around the house, planting the idea for Lance to look for medications that might be to blame. Maggie's menstrual period is late, and she considers buying a pregnancy test. She runs into an old classmate with a badly-behaved child, which adds to her anxiety about parenting, but she is relieved when she begins menstruating.
Maggie ends the relationship with Billy, and returns home. There she is confronted by Lance, who is painfully confused by the birth control pills he has found. She admits to her affairs, then confronts Milo, blaming him for ruining her marriage. Milo retorts that it was no "marriage" and she lashes back suggesting that next time he tries suicide to do it right. Maggie leaves Milo a voicemail echoing his suicide note, and goes to the pool where she'd been taking scuba lessons. Tying weights to herself, she jumps into the pool. As she begins to drown, she panics but is unable to free herself. Milo, having heard her message, jumps in the pool and rescues her.
The film closes with the twins at Milo's home, looking at his fish tank full of goldfish.Bill Hader as Milo Dean, Maggie's brother
Kristen Wiig as Maggie Dean, Milo's sister
Luke Wilson as Lance, Maggie's husband
Ty Burrell as Rich, Milo's former teacher whom he'd had an affair with in high school
Boyd Holbrook as Billy, Maggie's scuba instructor
Joanna Gleason as Judy Dean, Maggie and Milo's mother
Adriane Lenox as Dr. Linda Essex
Paul Castro Jr as Eric
The script of the movie went through a few iterations, including one where Milo was a drag queen and the film more closely resembled a road trip movie, but eventually Johnson and his writing partner settled on a more low-key approach inspired by the likes of Hal Ashby as well as Alexander Payne. Writing the film, Johnson wanted to avoid writing along genre lines as he believes both comedy and drama are present in everyday life. He has described the theme of the movie as "dealing with dark shit with a sense of humor."
One notable scene features the two characters lip syncing to Nothing's Gonna Stop Us Now by Starship. Initially the song intended to be used was "Hold On" by Wilson Phillips, however as the song had already played a focal point in Bridesmaids it was decided to choose another song. Accordingly, Johnson "spent 24 hours listening to every cheesy mid-’80s ballad you can think of and looking in the mirror and lip syncing it myself." The fact the Nothing's Gonna Stop Us Now is a duet opened up new possibilities with Johnson stating "the scene became a little more epic because it became about Bill’s character getting Maggie (Wiig) to sing Grace Slick’s part"
Principal photography began in November 2012 in Brooklyn, New York. Filming took place over the course of 22 days. Although a full script was written, Johnson encouraged improvisation on the set. Johnson has noted that an entirely improvised conversation between Wiig and Wilson involving Vibram shoes was his single favorite scene in the whole movie.
The Skeleton Twins received positive reviews from critics and has a "Certified Fresh" score of 86% on Rotten Tomatoes based on 146 reviews; the average rating is 7 out of 10. The site's critical consensus states: "Led by powerful performances from Kristen Wiig and Bill Hader, The Skeleton Twins effectively mines laughs and tears from family drama." On Metacritic, the film has a score of 74 out of 100 based on 33 critics indicating "generally favorable reviews".
The Skeleton Twins opened in a limited release in the United States in 15 theaters and grossed $380,691; the average take per theater was $25,379, and it ranked #25 at the box office. The widest release for the film was 461 theaters, and it ultimately earned $5,279,678 domestically and $468,848 internationally for a total of $5,748,526, above its estimated budget of $1 million.