Addison Forbes Montgomery

 Dr. Addison Forbes Montgomery (formerly Montgomery-Shepherd) is a character on the ABC television series Private Practice, the spin-off of Grey's Anatomy, where the character first appeared. Addison is a board certified OB/GYN specializing in maternal-fetal medicine, and is a world class pediatric surgeon, sub-specialising in neo-natal surgery and fetal surgery. The character is portrayed by actress Kate Walsh.

Background
A highly regarded neo-natal surgeon and fetal surgeon and a fellow of the American College of Surgeons, Addison is also a board certified OB-GYN with fellowships in maternal-fetal medicine and medical genetics. She also completed two years of study on cystic fibrosis. She is highly skilled in complex, often laproscopic, obstetrical, neo-natal and fetal surgeries. She has special expertise in Twin-to-twin transfusion syndrome(TTTS). She also has a Ph.D in medical genetics. She is one of the only surgeons in the world who can separate fetal blood vessels and correct Twin twin transfusion syndrome. She was formerly the surgeon incharge of a world class NICU at Seattle Grace Hospital.

In episode 5 of the spin-off, Private Practice, it is revealed that Addison is from Connecticut. It is implied that, like Mark Sloan, Addison comes from a wealthy background, in contrast to her former husband, Derek Shepherd, whose hard work and determination led him to success. It has been hinted at that Addison herself is very wealthy. She owns three properties: a New York brownstone, a house in the Hamptons and a house at Santa Monica. Richard Webber has stated that she is paid a salary that would make her one of the highest paid surgeons in Northwestern United States.

She was married to Derek Shepherd for eleven years before sleeping with Derek's best friend, plastic surgeon Dr. Mark Sloan, which prompted Derek to leave New York for Seattle. In spite of her chosen specialty and Derek's large family, Addison admitted to Miranda Bailey that when she and Derek discussed having children, she realized she wasn't ready. After she and Derek initially separated, she remained in New York and lived with Mark for two months, during which she became pregnant and aborted Mark's baby. The relationship ended when Mark cheated on Addison and Dr. Richard Webber brought her to Seattle Grace for a consult on a difficult case (and presumably, to break Derek and Meredith up). Richard was aware of Derek and Addison's strained relationship, though he did not know the cause of it ("Yesterday").

''Grey's Anatomy
Addison met her future husband, Derek Shepherd, in medical school and completed her residency under the supervision of her now good friend, Dr. Richard Webber, whom she, at one point, avoided for almost a year after he taught her a valuable lesson about not getting too close to her patients by putting her on a case in which the patient would inevitably die.

Addison and Derek became extremely successful in their respective fields and each began their own practice in New York. This strained their marriage. After she was caught cheating with Derek's best friend, Mark Sloan, he moved to Seattle to get away from her. There, he met Dr. Meredith Grey with whom he started a relationship. Addison then arrived in Seattle at Richard's behest, and confronted Derek on his affair by introducing herself to Meredith as his wife. This left Meredith feeling distraught and betrayed, and she ended things with Derek.

After a period of antagonism between her and Derek (in which he continually referred to her as "Satan"), Addison decided to stay on as head of neo-natal surgery at Seattle Grace, signing a lucrative two-year contract after she and Derek decided to make an effort to work things out, but Derek was still in love with Meredith. After finding out that her husband slept with Meredith at the hospital-sponsored prom, however, Addison (in a drunken haze) called Mark Sloan to Seattle. She and Derek then agreed that their marriage was over and started divorce proceedings. She asked Mark to go back to New York, but he stayed, expressing his desire to continue their relationship. Addison rebuffed him.

When the divorce was finalized, Addison dropped the "Shepherd" from her last name. Wanting to make a fresh start, Derek happily relinquished most of their shared properties (their Brownstone in Manhattan overlooking Central Park and a residence in The Hamptons) to her believing that she deserved it under his initial impression that she only had a one-night stand with Mark while he carried an affair with Meredith. Later, Addison divulged the whole truth regarding her infidelity to him which led to an emotionally painful encounter in which Derek told her to get out of his life. Addison is believed to have had a good relationship with the Shepherd family, in particular Nancy Shepherd (McBitchy), but, pending Derek's revelation of the true extent of Addison/Mark's relationship, her closeness to the Shepherds is in doubt.

Since arriving at Seattle Grace, Addison has made many friendships with other characters, most notably Callie Torres and Miranda Bailey. Her friendship with the two ladies has often been based on the fact that they act as each others' confidantes. Callie and Addison often discuss their current relationships and love lives, which has ultimately led to a very close friendship between the two. Addison is also very good friends with fellow attending, Preston Burke, and her ex-husband, Derek Shepherd. She has a strained friendship with Mark Sloan and doesn't have a strong friendship with any of the interns, with the exception of Alex Karev, but that friendship is reminiscent to that of hers with Mark Sloan. She has a father-daughter bond with Richard Webber, and is often portrayed to be very close to him.

A possibility of a relationship between her and Alex Karev has been hinted at, when she kissed him in Joe's bar. Even after he rejected her affections, she continued to lust after him from afar. She had (along with Mark) decided to abstain from sex for 60 days. If Dr. Sloan completes the challenge, she would be willing to try a real relationship with him; however, it is she who fails. She engages in a sexual encounter with Alex at the hospital and Mark learns of this after witnessing them stumbling out of an on-call room. She is spared from confessing, however, when Mark lies to her by telling her he had broken their promise long before. According to many of the show's allusions, Addison then decides to pursue Alex Karev. Her advances are once again rejected, however, hinting at the potential departure of Addison though she had expressed immense interest in being the next Chief of Surgery.

Private Practice
In the pilot episode, it was revealed that Addison can no longer conceive, as her antral follicle count was only two.

Addison is considered one of the best surgeons in her field in the world (patients often travel across the country to receive medical and surgical care from her), but with her relocation to Los Angeles her surgical practice has become limited, with practicing as an OB/GYN for the time being.

After briefly showing interest in her coworker Pete, Addison gave up on any potential romance between the two after Pete stood her up for a date. She is currently interested a police officer who had asked her out on a past episode.

Surgical Specialization
Addison is certified in OB/GYN, Maternal/Fetal Medicine (Perinatal medicine), fetal surgery, neonatal surgery, pediatric surgery and medical genetics. Addison seems to be highly specialised in many surgical specialties. It is unlikely that a practising doctor would have so many specialties, but still possible, nonetheless, in reality, a surgeon with such extensive training would be older than a 30-something Addison. A possible route could have been this: completing an OB/GYN residency, then returning to complete a surgical residency and a fellowship in pediatric surgery. Maternal-fetal medicine stems off as a sub-speciality of obstetrics where neo-natal surgery can stem off of pediatric surgery. Fetal surgery is a super sub-specialty of pediatric surgery. Addison also completed years of study in medical genetics, specialising in cystic fibrosis.

Personality
Although Addison is famous for being difficult and often uncompromising, she has revealed softer aspects of her personality from time to time. She has openly claimed to be the best in her field on various occasions, and has promptly mentioned her resumé to people who have questioned her abilities.

One of the most competitive surgeons, Addison has sometimes challenged her colleagues, most notably Alex Karev, who has spent a long part of his internship with her. However, she also has an excellent bedside manner and, like Dr. Isobel "Izzie" Stevens, is known for becoming emotionally attached to a lot of her patients. Her father-daughter relationship with her mentor, Dr. Richard Webber, has often offered sanctuary to Addison, and has helped her reveal some of her insecurities.

She has chosen to remain honest about her separation from her ex-husband and the details of her infidelity and has confessed to feeling guilty about her affair with Mark Sloan. As Miranda Bailey has observed, Addison tends to define herself by the men in her life. Her love life is often troubled, and she finds it difficult to commit to any long-term relationship.