For what age: 19+
How many episodes in 4 season: 20 episodes
Tensions run high as Stef and Lena are called to action when the school is put on lockdown after it's discovered that Mariana's boyfriend Nick brought his father's gun on campus, after seeing her kiss her ex-boyfriend Mat. Callie admits her past relationship with Brandon to her moms. But before Stef and Lena can even process the information, the school goes into the "Code Blue" lockdown.
After being given the all clear to head home, tensions are still running high in the Adams Foster household. Fragile and skittish from the school lockdown, the family sticks close, but their secrets keep them apart. Callie and Brandon anxiously wait for their moms to address their behavior in Idyllwild while Stef warns everyone to stay off their phones and computers due to the rumors swirling around their family. Meanwhile, Brandon sneaks out to help Cortney move, leading to a major blowup between him and Stef.
Callie ends up being suspended from school after she reacts inappropriately to taunts from some of the students. Mariana is blamed for Nick's actions.
Callie starts her senior project of photographing the outside of her and Jude's seven former foster homes. But, when an unexpected encounter with a former foster mother brings her inside, Callie decides to reach out to other people who have fostered her and is shocked to learn that a 17-year-old former foster brother has been convicted of cuddle. Stressed out by the hardships of supporting himself and Cortney, Brandon throws a house party and things take a turn for the worse. Stef and Lena offer to pay for an attorney to help get Gabe off of the sex offender registry, which is currently putting Lena's job at risk and causing friction between Mike and Ana. Meanwhile, Mariana tells her moms that, in order to feel safe again, she wants to visit Nick and put an end to their relationship once and for all.
Lena is excited that her family is coming together to throw her a 70s-themed 40th birthday party. But, when Lena's mom Dana shares her suspicions about Stewart's behavior, it threatens to put a damper on the festivities. Convinced her former foster brother Kyle has been wrongly convicted of cuddle, Callie and Aaron try to track down a witness in the case. Mariana and her female STEAM club teammates compete for an invite to the Regional Robotics Competition.
Lena and Stef are shocked by a secret Lena's father has been hiding that could jeopardize the entire family. Meanwhile, Lena confronts Brandon about the money he gave Cortney; Mariana must deal with the male members of her STEAM team; Jesus begins to resent Emma; and Jude discovers Noah has a medical marijuana card.
Jesus sustains an injury after he tries to cover for his father who didn't show up for work. Meanwhile, Mariana takes Jesus' ADHD medication after feeling drained; Callie and AJ are caught in an awkward situation when Brandon and Mike arrive home early; and Stef tells Mike that Brandon gave his settlement money to Cortney.
Mariana and Jesus compete in the First Robotics Southern California Regionals, but when Mariana gets too competitive under the stress, Lena grows alarmed. Callie gets a warning from the police to stop harassing Patrick Molloy. Brandon practices for his fast-approaching Julliard audition.
Brandon travels to New York City for his Julliard audition and meets a girl who forces him to take a hard look at his life, including his relationship with Cortney. Meanwhile, Stef and Lena make an unexpected announcement that leaves the family in shock. And Callie's friendship with Aaron causes friction between her and AJ.
Callie and the family set-up a Justice for Jack booth at the music festival in the hopes of stopping Justine's foster-care bill; and Callie's interest in re-opening Kyle's cuddle case puts her in danger.
In the aftermath of Jesus' fight with Nick over Mariana, Jesus is knocked out. On the way to the hospital, things take a turn for the worse, leaving him fighting for his life. Meanwhile, Callie finds herself in a dangerous situation after taking a ride with Troy and Mariana is guilt-ridden over the fact that her actions led to Jesus' current condition.
A comatose Jesus has dreams that correlate with the things going on in his hospital room and things that have gone on in his family.
Callie awaits her hearing in juvie while Jesus remains in the hospital; Stef and Lena struggle to cope with all of the issues going on in their family.
Mariana starts seeing a therapist to deal with the trauma of Nick's actions. Brandon discovers a type of musical therapy that he thinks can help Jesus.
Brandon supports Emma through a difficult situation, which makes Jesus suspicious about their friendship. When Jude learns that LGBT sex is not covered in his school's sex education class, he tries to gain knowledge through a dating app instead.
Sharon and Will return to the Adams Foster home with news that they are engaged. While the family happily prepares for the wedding ceremony, Stef learns that her mom is having second thoughts about getting married. In an effort to come clean with Jesus, Emma writes him a letter but learns he is hiding a secret of his own. Meanwhile, Jude is teased at school when Lena organizes an LGBTQ-friendly sex ed class for students.
Stef starts a new assignment in human trafficking where she meets a young girl turning tricks on the streets.
Lena is at her wit's end when everyone comes to her to handle all their crises and Stef is never around to help. Aaron invites Callie on a road trip to visit his parents.
It seems just about everyone in the Adams-Foster household has a secret, but unfortunately for each of them, they all start spilling out. With Callie's court date inching closer, Robert's attorneys present a defense strategy that Callie vehemently opposes. Monte and Lena join forces to stop Drew's underhanded dealings. Stef works to bust Diamond's pimp. Jesus asks Gabe to keep a secret from his moms.
Callie faces a life-changing decision to take a plea deal and go to jail for three years, or go to trial and risk an even longer sentence. Even though Callie struggles with her own situation, she tries to help Diamond.
