Addison Adrianne Forbes Montgomery, MD, PhD, FACS, FACOG,Season 3, Episode 10: "Blowups" previously known as Shepherd, is a fictional character who first appeared as a supporting main character on the ABC television series Grey's Anatomy, and as the protagonist of its spin-off Private Practice played by Kate Walsh. Addison is a world-class neonatal surgeon with board certifications in both obstetrics and gynaecology and maternal–fetal medicine. In addition, she has completed a medical genetics fellowship.
Addison initially joined Grey's Anatomy in the Season 1 finale as the estranged wife of Derek Shepherd (Patrick Dempsey). Although she was originally planned as a recurring guest character, creator Shonda Rhimes grew fond of Walsh's portrayal, which led to Addison becoming a series regular by season 2 episode 7, "Something to Talk About". Addison's character played a significant role throughout seasons 2 and 3, with her final appearance as a regular in the season 3 finale, "Didn't We Almost Have It All?". Despite her departure as a series regular, Addison continued to make guest appearances over the next 5 seasons, including a notable two-part guest stint in Season 5.
After the love triangle involving Addison, Derek, and Meredith Grey (Ellen Pompeo) was resolved, Rhimes created the first spin-off of Grey's Anatomy centered around Addison, titled Private Practice. The new series saw Addison move to Los Angeles to start fresh, working at the Oceanside Wellness Group, a fictional private practice in Santa Monica, California. Private Practice ran for six seasons, from 2007 to 2013, airing concurrently with Grey's Anatomy's seasons 4 through 9.
Walsh decided to retire the character after 8 years of portraying Addison, making her final series regular appearance in the Grey's Anatomy universe during the Private Practice series finale, "In Which We Say Goodbye", on January 22, 2013. However, nearly 9 years later, Walsh returned to the role of Addison in a recurring capacity for the Seasons 18 and 19 of the original series.
Storylines
Backstory Most of Addison's past is revealed in a non-linear fashion, primarily throughout the second season of Grey's Anatomy and the second and third seasons of Private Practice. Addison comes from a wealthy background and has a $25 million trust fund. Her father, nicknamed "The Captain", is a doctor who teaches medicine at a university, where Addison would watch him as a child. However, her father's time with Addison was often a pretense for his numerous affairs. Her mother, Beatrice "Bizzy" Forbes Montgomery, is also a prominent figure, and her brother, Archer, is a renowned neurologist and a successful author.
Addison met her future husband, Derek Shepherd, in medical school, and their love story began during their time at Columbia University College of Physicians and Surgeons in New York City. Addison is also a graduate of Yale University. During her time in New York, she formed close friendships with Sam and Naomi Bennett, who would later become her colleagues at the Oceanside Wellness Group in Private Practice.
Despite their early connection, Addison and Derek's marriage became strained as they started their medical practices in New York City. This professional life contributed to the growing distance between them. The couple's troubles were further compounded by Derek's family disapproving of Addison, particularly his mother, who gave her deceased husband's ring to Derek's second wife, Meredith Grey. Additionally, Addison's brother, Archer, disliked Derek, which created further tension.
The pivotal moment in their relationship came when Addison had an affair with Mark Sloan, Derek's best friend, further damaging their marriage. Addison briefly tried to build a relationship with Mark, but it quickly fell apart when she discovered she was pregnant and learned that Mark had cheated on her. She decided to have an abortion, still being in love with Derek, and subsequently moved to Seattle in an attempt to repair her relationship with him, which ultimately failed.
Grey's Anatomy Addison first appears in the Season 1 finale of Grey's Anatomy, arriving in Seattle at Richard Webber's request. Her initial goal is to reconcile with her estranged husband, Derek, despite his budding relationship with Meredith. Although Derek is still angry with her for her affair with Mark, Addison’s arrival stirs up old feelings, and the couple attempts to rekindle their marriage. This leads to Derek ultimately choosing Addison over Meredith, though he admits that he has fallen in love with Meredith. They try to rebuild their life together, with Addison becoming the head of a new surgical service that integrates neonatal surgery with obstetrics and gynecology.
However, Derek's lingering feelings for Meredith continue to challenge their relationship. Matters are further complicated when Mark Sloan arrives in Seattle to pursue Addison. Mark tells her that Derek is still in love with Meredith, and that he (Mark) genuinely loves her. Addison eventually acknowledges the truth: that Derek’s heart belongs to Meredith. As Derek tries to deal with seeing Meredith move on, he has sex with her in a moment of vulnerability at a hospital foundation gala. When Addison learns about this, she retaliates by having a one-night stand with Mark. Though Mark expresses his desire for a serious relationship, Addison declines, as she recognizes the complexity of her feelings for both men.
In Season 2, Addison initially punishes Alex Karev by placing him on her service after he almost causes her legal trouble. However, as season three unfolds, Addison develops a romantic attraction toward Alex, leading to them sleeping together. Addison quickly realizes that Alex does not want a relationship with her, leaving her feeling even more isolated. Wanting to have a baby, Addison consults her friend Naomi Bennett, a fertility specialist, which introduces the storyline that serves as the backdoor pilot for Private Practice, marking her transition from Grey's Anatomy to the spin-off.
Addison eventually decides to leave Seattle and moves to Los Angeles, where she joins the Oceanside Wellness Group, led by Sam and Naomi Bennett. This officially ends Addison's time as a series regular on Grey's Anatomy, though she makes guest appearances on the show through Season 8.
For reasons unknown, Addison is not present at Derek's funeral. In September 2021, it was announced via social media that Kate Walsh would reprise her role as Dr. Addison Montgomery in Grey's Anatomy's eighteenth season. Addison returned for 3 episodes: "Hotter than Hell," "With a Little Help From My Friends," and "Should I Stay or Should I Go?".
In season 19, Addison returns in five episodes. In episode 3 (Let’s Talk About Sex), Bailey decides to create a series of sexual health videos with the interns and enlists Addison in her efforts. Bailey and Addison take a road trip to a family planning center out of state in “When I Get to the Border”(episode 5). In episode 11, titled "Training Day," Addison returns to Grey Sloan Memorial to assist Miranda Bailey in training new OB fellows. After news of her presence at the hospital spreads online, a large group of protesters gathers outside the clinic due to her work as an OB/GYN. The situation turns violent when a protester throws a brick with the words "Montgomery murders" written on it through a clinic window. Addison helps deliver a baby amid the chaos, but while she and her team are being escorted from the clinic, a protester drives a car into her and a pregnant OB/GYN trainee. Despite the severity of the attack, Addison survives. Episode 12 (Pick Yourself Up) is a continuation of episode 11 with the hospital being placed on lockdown. Addison makes her final appearance on Grey’s Anatomy in episode 16 “Gunpowder and Lead.”
Private Practice In the series, Addison is initially made to feel unwelcome by the other doctors at Oceanside Wellness Group, but she decides to stay and work through the challenges. Early on, Addison is attracted to Pete Wilder, the practice's alternative medicine specialist. However, after Pete stands her up on a date, Addison decides to remain friends with him and begins dating Kevin, a police officer she met through work. In a crossover episode, Addison briefly returns to Seattle Grace to assist with a patient and gives Meredith advice not to let Derek slip away.
In Season 2, Addison learns from Naomi that the practice is struggling financially. Despite Naomi’s request to keep it a secret, Addison informs Sam, which leads Naomi to feel betrayed and end her friendship with Addison. This situation escalates when Addison inadvertently prompts the staff to vote between Sam and Naomi for leadership of the practice, and she is surprised when the staff elects her as the new director.
Addison's relationship with Kevin is tested when her brother Archer tells him he isn't good enough for her. Although Addison initially reassures Kevin, the strain eventually causes them to break up. Archer soon begins working for a rival practice, the Pacific Wellcare Center, and when he suffers multiple seizures and believes he has a brain tumor, Addison asks Derek Shepherd to treat him in another crossover episode with Grey's Anatomy. Derek discovers that Archer has parasites in his brain and successfully removes them, saving his life. During this time, Archer begins dating Naomi, putting further strain on the already fragile friendship between Naomi and Addison.
Addison also begins dating a man who turns out to be married to her patient. Despite knowing this, Addison continues to cross the line until the patient calls Addison out on it. Additionally, she discovers that her mother, Bizzy, is a lesbian and has been in a long-term affair with her best friend. Addison had previously blamed her father for his numerous affairs and was unaware of her mother's secret relationship. Though her relationship with her parents becomes strained, Addison ultimately makes peace with them.
As the series progresses, Addison starts developing feelings for Sam, Naomi’s ex-husband. It is revealed that Sam had wanted to ask Addison out back in college, but ended up with Naomi instead. Addison and Sam share a kiss after a traumatic event, and their feelings for each other grow. However, Addison is hesitant to pursue a relationship with Sam because of her friendship with Naomi. Despite these concerns, Addison eventually admits that she loves both Sam and Pete but decides to begin a relationship with Pete while Sam is dating another doctor.
Although Addison and Pete try to make their relationship work, she and Sam continue to harbor feelings for each other, and after Sam becomes single, they kiss again. Pete catches them, but Addison and Pete stay together for a while longer. Naomi ends her friendship with Addison after learning about her relationship with Sam. In the Season 4 finale, Addison has to operate on her godchild, Maya Bennett, after a car accident, which helps mend her friendship with Naomi. Addison eventually breaks up with Pete and finally becomes a couple with Sam. However, their relationship is strained when Addison expresses her desire to have children, while Sam is not ready for that commitment.