Season 4 begins with the gang sharing an emotional reunion in Miami at Ally's homecoming gig. But when Austin learns the foursome's time together is only temporary, he considers enrolling in military school.
Austin takes a job at his parents' mattress store; Ally struggles to keep up with an influx of music students.
The gang try to teach first-time music students how to play in a band in anticipation of the A&A Music Factory's grand opening.
Austin learns he is a credit short of becoming a senior with his friends.
Ally tries to unlock the hidden musical talent of a new student.
Trish books a famous brother-and-sister duo to talk and perform with students at the music factory. Meanwhile, a code inspector arrives to review the music school and threatens to shut it down.
Austin and Ally imagine life together as a married couple when they are paired together in Home Ec. Meanwhile, Trish helps Dez book a job directing a commercial.
Austin, desperate to perform again, begins singing at a karaoke club. Meanwhile, Ally mentors a student with stage fright.
Austin wants to surprise Ally by teaching their students one of her songs, as they prepare for the A&A Music Factory's first showcase.
Ally performs at an awards show but the producers worry about her dancing abilities. Becky G performs.
Ally's songbook is stolen from her school's 1970s-themed party, so the gang sets out to find the culprit.
Austin visits a fortune teller and becomes convinced that something bad is going to happen during his comeback concert. Meanwhile, Trish believes she is going to meet a prince.
Trish tries to prevent her boy band client Boynado from breaking up. Meanwhile, Austin and Ally help a former impersonator find his own voice.
Ally learns that the new woman her Dad is seeing also happens to be the mom of a very difficult student at the A&A Music Factory.
The gang visits New York City and attends the Spooktacular in Central Park where they tell their own scary stories.
When Ally is rejected from college, she decides to let go of her "perfect student" ways. Meanwhile, Austin and Dez discover their favorite childhood ride will shut down forever.
Ally is determined to graduate and attend Harvard, where a lost library book gets in her way.
One of Austin & Ally's music students is upset about spending Christmas away from her father, so the gang does everything they can to try and make her happy and realize that they're her family too.
As the rest of the group prepares for the next phase of their lives, Trish is still determining what her next steps will be.
Years after the gang has gone their separate ways, Ally, Austin, Trish and Dez meet-up and learn what they have all been up to, individually.
