The Rooney house is rebuilt and Karen can't wait to have the family reunite in Wisconsin. However, when exciting opportunities arise for each of the Rooney kids, their summer plans are suddenly thrown into jeopardy.
Liv undergoes vocal surgery and is unsure if she will ever be able to sing again, so Karen and Maddie call in reinforcements to help. Meanwhile, Parker and Val are surprised by their competition in the Mars Madness finals.
Joey feels awkward when Maddie and Josh rekindle their friendship and start hanging out together. Meanwhile, Parker and Val get in a jam when they compete for a coveted finalist spot in the Mars Madness competition.
Joey gets nervous when he is invited to perform stand-up comedy at a local restaurant. Meanwhile, Parker lands in a predicament when he isn't sure if he asked a fellow classmate to be his partner in a science competition or his date to a school dance.
Maddie gets upset when she can't be in Wisconsin for Christmas, so Liv does something to help cheer her up. Meanwhile, Joey participates in a Mr. North Pole Santa Claus pageant against an old foe; and Parker tries to teach Ruby the wonders of a snow day.
When Liv's new show may get canceled because the right cast can't be found, Liv helps by searching for the perfect star. Meanwhile, Parker plots to take Joey and his new Falcon persona down by having Joey test drive a dangerous invention.
Liv takes Ruby to a spooky dinner and runs into an old acquaintance, and Maddie comes face-to-face with the real-life "spider-sprayer." Meanwhile, Parker and Joey must convince their classmates to celebrate Halloween.
Season 4 begins with Liv, Maddie and the rest of the Rooney family excited to start their new life in California. As the school year begins, the Rooney's cousin Ruby returns home from summer camp and is thrilled to have "sort of" siblings. Meanwhile, Joey and Parker attend their new science and technology school but it's nothing like what they expected.