Matthew Carlson functions as showrunner. The collection celebs Paris Berelc as well as Isabel May as Alexa in addition to Katie, specifically, with Jolie Jenkins, Emery Kelly, Eddie Shin, Finn Carr, Tiffani Thiessen, with Jack Griffo similarly starring. The collection debuted on Netflix on March 23, 2018, with the very first duration including 13 episodes.
On April 9, 2018, Netflix recovered the collection temporarily period, which premiered on December 26, 2018. On February 15, 2019, Netflix restored the collection for a third as well as last season, divided into 2 eight-episode parts. The first part of the third season was released on December 30, 2019, with the second part set to be released on June 13, 2020.
Lifelong best friends Alexa as well as Katie are eagerly anticipating the start of their freshman year of high school. The two friends confront a crisis when Alexa discovers that she is ill with cancer and starts undergoing treatment for the illness, which leaves them feeling like outsiders at a time when what seems to matter most is fitting in. To support Alexa, Katie makes an important decision and cuts off all of her hair with Alexa. The girls try to navigate through all the troubles high school seems to bring while dealing with cancer.
- Paris Berelc as Alexa, an ambitious basketball player battling cancer. A determined individual, she strives to live a normal life which often gives her rebellious tendencies. She also despises the pity she receives because of her illness.
- Isabel May as Katie, Alexa's best friend. Portrayed as quirky and awkward, she consistently supports Alexa's impulsive decisions when dealing with the illness. Katie also shares a liking for theatre. She seems to be attracted to Lucas.
- Jolie Jenkins as Jennifer, Katie's divorced, single mother studying to finish college while working. Because of her home situation, Jennifer's family is less financially fortunate than the Mendozas.
- Emery Kelly as Lucas, Alexa's older brother. Often portrayed as dimwitted and conceited, he cares a great deal for Alexa and aspires to be a doctor, wanting to help others as the doctors helped her. In season two, he becomes the leader of his own band.
- Eddie Shin as Dave, Alexa, and Lucas' father, Lori's husband, and an airline pilot. When Alexa shaves her head, he struggles to cope with reality but eventually realizes his faults. He is also shown to have competitive tendencies like his wife, Lori.
- Finn Carr as Jack, Jennifer's son, and Katie's younger brother with an avid love for candy and video games. Despite his age, he understands Alexa's situation and helps her the best he can. He eventually adopts a dog, Potato.
- Tiffani Thiessen as Lori, Alexa, and Lucas' mother and Dave's wife. Strong-willed, competitive, and at times overprotective, she helps guide Alexa through her fight with cancer and additional problems as a teen.
- Jack Griffo as Dylan (recurring in season 1 & 3; main in season 2), Lucas' highly intelligent best friend. He begins tutoring Alexa in season one when her grades drop. Later, Dylan asks Alexa to the Winter Formal and the two begin dating. In season two, Alexa breaks up with Dylan when he doesn't know what will happen to them when he goes to college, but they eventually agree to be friends.
Alexa & Katie is the first multi-camera sitcom produced by Netflix. The series was ordered in early 2017 with Wordham as executive producer. Berelc and May would star as the protagonists with Carlson serving as showrunner. In June 2017, Thiessen, Shin, and Kelly were cast as Alexa's parents and older brother, with Jenkins cast as May's mother. In August 2017, Griffo, Medders, and Leighton were cast as Berelc and May's classmates. On April 9, 2018, Netflix renewed the series for a second season, with Wordham replacing Carlson as showrunner.
On February 15, 2019, the series was renewed for a third season of 16 episodes. The season will be split into two parts, each featuring eight episodes and focusing on Berelc and May's characters navigating through their last years of high school. The first part of the Third period premiered on December 30, 2019. The second component of the third duration prepares to premiere on June 13, 2020.