Farrah takes her daughter Sophia on a trip to visit Sophia's dad's grave, and Amber and her mom get in an argument. Maci struggles to keep up in college, while Catelynn and Tyler want to invite their daughter to graduation.
Maci decides to enroll Bentley in daycare while Amber prepares to go to rehab. Catelynn and Tyler celebrate Carly's second birthday, and Farrah has a change of heart about leaving daughter Sophia behind when she moves.
Amber and Gary work on their relationship issues. Maci struggles to choose classes. Visiting her parents, Farrah is annoyed with their concerns for Sophia. Catelynn and her grandmother attend a birth parent support group.
A visit from Farrah's mom and sister leads to a blowup, and Maci enrolls her son Bentley in preschool. Catelynn and Tyler face issues with Butch, while Amber debates leaving rehab early.
Teen Mom Maci confronts her ex about child support. Amber chooses between her baby's dad and her new boyfriend. Catelynn and Tyler consider moving in together while still in high school, and Farrah considers making a big change.
Farrah and her parents argue while on a trip, and Catelynn reunites with her father. Amber reaches out to Gary to re-unite her family on the anniversary of a tragedy, while Maci considers withdrawing from school.
Catelynn and Tyler have an emotional visit with their daughter. Amber struggles during her first weeks of rehab. Farrah says farewell to her life in Iowa. A disagreement with Ryan disrupts Maci and Kyle's relationship.
Amber goes on a date, while Catelynn and Tyler get their parents involved with planning a perfect Christmas. Maci makes a shocking announcement, and Farrah breaks the news to her parents that she wants to move to California.
Gary and Leah visit Amber in rehab, and Farrah goes on a date with her neighbor. Maci tags along on Ryan's family vacation and Catelynn and Tyler question letting Butch move back into their home.
Dr. Drew hosts in front of a live audience. Catelynn and Maci discuss new milestones, custody battles, school struggles, and family problems that we saw them face in Season 3. Ryan and Kyle share the stage for the first time.
Maci has a blowout with Ryan over custody, while Amber and Gary struggle with a no-contact order. Catelynn finally finishes high school, and Farrah's parents try to talk her into leaving Sophia behind when she moves away.
Maci and Ryan argue over who has rights to Bentley on his birthday, and Amber breaks down over being separated from Leah. Farrah struggles to spend time with Sophia, and Catelynn and Tyler look for jobs.
Catelynn struggles to fix her relationship with her mom, while Amber & Gary meet with Child Protective Services. Maci finally decides to move away from Kyle and back home to Chattanooga, and Farrah goes to court.
Maci and Kyle contemplate buying a house. Farrah introduces Sophia to her new boyfriend. Amber struggles to find a way to see her daughter. A fight between Catelynn and Tyler's parents throw their family future into question.
Maci and Ryan clash over Bentley attending preschool. Tyler pressures Catelynn to enroll in college. Farrah begins dating a new guy. After completing two months in rehab, Amber finally heads back home.
Farrah introduces her boyfriend to Debra. Catelynn supports her own mom as Tyler's dad goes to court. Bentley has a hard time adjusting to Maci's new house. Amber and Gary continue to struggle with sharing custody of Leah.
Catelynn and Tyler attend their high school graduation. Maci considers joining Ryan on his family vacation. Farrah has to deal with her parents' overbearing concerns. In rehab, Amber expects a visit from Gary and Leah.
Amber is upset when Gary refuses to celebrate Leah's birthday together, and Catelynn copes with her fears about adoption. Farrah gets a puppy, while Maci's Ex finally discovers that her boyfriend is living with her.
Amber finds out that she is being investigated, and fears she will lose custody. Ryan wants to meet Maci's new boyfriend, while Sophia's paternal grandmother is suing for visitation rights. Tyler's dad gets out of jail.
Dr. Drew hosts the Teen Moms in front of a live audience. Farrah and Amber reflect on the past year of motherhood - the struggles and family strife that we saw them face in Season 3, and everything that has happened since.