Development and writing

The season was produced by Touchstone Television ABC Studios, The Mark Gordon Company, Shondaland and was distributed by Buena Vista International, Inc. The executive producers were creator Shonda Rhimes, Betsy Beers, Mark Gordon, Krista Vernoff, Rob Corn, Mark Wilding, Joan Rater and James D. Parriott. The regular directors were Shonda Rhimes, Krista Vernoff, Stacy McKee, William Harper, Debora Cahn, Allan Heinberg and Peter Nowalk.^[24] At the conclusion of season 5, T. R. Knight was released from his contract, following a disagreement with Rhimes. When asked to make a 'flashback' appearance in season six, Knight declined.^[25] Heigl's appearances in the season were sporadic, seeing Stevens depart and return twice.^[26] Although she was scheduled to appear in the final 5 episodes of the season, Heigl requested that she be released from her contract 18 months early, and made her final appearance on January 21, 2010.^[27] Heigl explained that she wanted to spend more time with her family, and did not think it would be respectful to Grey's Anatomy viewers to have Izzie return and depart yet again.^[26] The season's 2-hour opener showed the doctors of Seattle Grace Hospital, grieving the loss of their deceased friend, O'Malley. The special's writer, Vernoff, commented: "It's heartbreaking. I fell in love with George, like many of you did, in season one."^[28]

The ninth episode of the season, "New History", saw the arrival of Altman, which ended up forming a love-triangle between her, Hunt, and Yang. Raver commented on this: "She was in Iraq with Owen. She's a cardiac surgeon. She's really good at what she does. There'll be some interesting stuff between Teddy, Owen and Cristina."^[29] The episode's writer, Heinberg, offered his insight:

"Teddy's arrival at Seattle Grace unleashes all manner of complications for Owen, Cristina, and herself. Cristina's immediately suspicious that Owen and Teddy were more than friends during their time together in Iraq. Teddy confesses to Owen that she apparently misread their mutual history, and walks away from him, mortified. And Owen's left haunted by Teddy's confession, now forced to re-examine his own history -- and his feelings for both Teddy and Cristina.

— Allan Heinberg, Grey Matter

"I Like You So Much Better When You're Naked" saw the departure of Stevens, following the breakdown of her marriage with Karev. Series' writer Joan Rater commented on this: "Izzie getting the clean scan back gives Alex the freedom to leave. Because he never would have left her when she was sick, he's a good guy. And I'm not saying that Alex ever consciously thought, I can’t leave her while she's sick, but now that she's not, now that she seems like she's going to get better, it just comes to him. He deserves more. He's a good guy and he deserves more. But loving Izzie showed him that he can be good, is good. So it was a little gift. And when he tells Izzie he's done, he's not bitter or angry, he's just done."^[30]

The writing of the 2-part season 6 finale, caused struggle to Rhimes. She elaborated on this:

It hurt to write this finale. It literally hurt me. Because in order to write these episodes, I had to walk in the shoes of [the shooter]. I had to think like a shooter. A person who would shoot Reed and Alex and Charles. A person who would shoot Derek. By the time I finished writing part one, I was sick. And depressed. Because my McDreamy was lying on my beloved catwalk dying. Mer is screaming and he is dying. And, before you have me shot up with Thorazine and placed in a strait jacket, yes, I DO I know it's only a TV show, I'm not insane, but dude…it felt too real. It felt WAY too real.^[31]

Casting

The sixth season had 13 roles receiving star-billing, with 12 of them returning from the previous season, 1 of whom previously in a recurring guest capacity. The regulars portray the surgeons from the fictional Seattle Grace Hospital as new rivalries and romantic relationships begin to develop after the hospital's merger with Mercy West. Meredith Grey, a surgical resident and the protagonist of the series, is portrayed by Ellen Pompeo. Fellow third-year residents Cristina Yang, Izzie Stevens and Alex Karev are portrayed by Sandra Oh, Katherine Heigl and Justin Chambers, respectively. Attending general surgeon Miranda Bailey was portrayed by Chandra Wilson whose main storylines throughout the season focus on her divorce and the development of new romantic relationships. Seattle Grace Hospital's Chief of Surgery and general surgeon Richard Webber was portrayed by James Pickens, Jr., who returns to alcoholism after being sober for 20 years.

Sara Ramirez acted as bisexual orthopedic surgeon Callie Torres, Eric Dane played womanizer plastic surgeon Mark Sloan, Chyler Leigh portrayed Meredith's half-sister and second-year surgical resident Lexie Grey, Kevin McKidd appeared as trauma surgeon Owen Hunt, and Patrick Dempsey featured as chief of neurosurgery Derek Shepherd. After having previously appeared in a multi-episode arc in a guest-star capacity in the show's fifth season, Jessica Capshaw began receiving star-billing in the season's premiere episode in the role of attending pediatric surgeon Arizona Robbins. The ninth episode of the season marked the introduction of the new chief of cardiothoracic surgery Teddy Altman, portrayed by Kim Raver, whose mysterious romantic past with Hunt develops into one of the season's main stories. Starting with the nineteenth episode of the season, Raver began receiving star-billing.

The sixth season introduces several new recurring characters who start to develop progressive and expansive storylines throughout the season. Mercy West surgical residents Reed Adamson, Charles Percy, April Kepner and Jackson Avery were portrayed by Nora Zehetner, Robert Baker, Sarah Drew and Jesse Williams, respectively. Jason George portrayed Miranda Bailey's love-interest, anesthesiologist Ben Warren. Thatcher Grey (Jeff Perry) and Sloan Riley (Leven Rambin) have been part of the season's main story arcs, while numerous episodic characters have made guest appearances: Demi Lovato as Hayley, Sara Gilbert as Kim Allen, Marion Ross as Betty, Mandy Moore as Mary Portman, Ryan Devlin as Bill Portman, Nick Purcell as Doug, Michael O'Neill as Gary Clark, Danielle Panabaker as Kelsey, Adrienne Barbeau as Jodie Crawley, Héctor Elizondo as Mr. Torres, Cody Christian as Brad Walker, Amy Madigan as Dr. Wyatt, and Missi Pyle as Jasmine. Former series-regular Kate Walsh returned to the series as a special guest-star, portraying neonatal surgeon and obstetrician-gynecologist Addison Montgomery.

Ratings

The sixth season opened up to 17.04 million viewers with a 6.7/17 Nielsen rating/share in the 18–49 demographic.^[32] Although the rating was a 1% decrease from season five's opener, it managed to rank first for its time-slot and the entire night, in terms of both ratings and viewership, and served as the season's most viewed episode.^[32] "Sympathy for the Parents" was the season's least viewed episode, and up to that point, the series' as well, garnering only 9.87 million viewers.^[33] The season's finale garnered 16.13 million viewers, and received a 6.2/18 rating, ranking first for its time-slot and the entire night, in terms of both ratings and viewership.^[23] Although the finale was a success for the night, it was a 1% decrease from season five's finale, but served as the season's second most viewed episode.^[34] Overall, the season ranked at #17 for the year, and had an average of 13.26 million viewers,^[35] a 5% decrease from the previous season's ranking.^[36]

Critical response

The season received mixed-to-positive reviews among television critics. Speaking of the premiere, Glenn Diaz of BuddyTV noted that the special foreshadowed a "very dark" season, adding: "The talk between George's mom and one of the surgeons [Torres] proved to be one of the more heart-breaking scenes in an episode that in itself is heartbreaking enough."^[37] In contrast, Kelly West of TV Blend was critical of the premiere, writing: "I don’t think based on the first episode that we can say that Grey's is headed in a new direction, nor do I think the writers are making much of an effort to bring the series back to the greatness that was its earlier seasons. That said, this is Grey's Anatomy and with that comes the usual drama, sex, love and whacky medical mysteries thrown in the mix to keep things moving. If that's what you’re looking for, I think you’ll enjoy the season premiere just fine."^[38] Capshaw's performance this season was praised, with The TV Addict calling her "immensely likeable".^[39] Although "Sympathy for the Parents" was the least viewed episode, TV Fanatic called the episode "touching", praising Chambers' performance.^[40] TV Fanatic's reaction to the season was fairly mixed,^[41][42] with Steve Marsi saying that Grey's Anatomy was facing an identity crisis after viewing "Give Peace a Chance".^[43] He said that: "Still popular but lacking its past magic, it's trying to decide what to become. All we can say is that if it becomes what we saw 12 hours ago, we are all for it. Last week saw the doctors plunging into ER-style chaos with 12 different doctors giving 12 different accounts of one case. Last night, we saw something else equally unusual."^[43] He praised Patrick Dempsey's performance, saying: "Again, it was a single case that took up the entire hour, but instead of 12 doctors' version of events, the focus was largely on just one, and the best one: Dr. Derek Shepherd. Patrick Dempsey's McDreamy character may be eye candy, but he's got substance. Last night's episode proved that in spades, and was one of the series' best in some time."^[43]

The season's finale Death And All His Friends was highly praised. Marsi gave the episode five stars, and expressed that it may have been the best episode of the series, adding: "The writing and acting were absolutely stellar, and may lead to many Emmy nominations, but even more impressively, despite a killing spree, it remained distinctly Grey's. Some of the back-and-forths between the characters were truly memorable, and some of the developments so heartbreaking that we don't even know where to begin now. Seriously, the Season 6 finale left us laying awake afterward thinking about everything, a feeling we haven't had from Grey's in years and rarely achieved by any program."^[44] John Kubicek of BuddyTV also noted that the finale was the best episode, adding: "[It was] two of the best hours of television all year. It was certainly the best Grey's Anatomy has ever been, which is saying a lot since I'd written the show off for the past few years. No show does a big traumatic event like Grey's Anatomy, and the shooter gave the show license for heightened drama with five major characters being shot over the two hours. It was emotional, expertly paced and had me in tears for most of the finale."^[45] Entertainment Weekly wrote, "At any rate, now you can at least see where it all began. And while you’re still pondering how Grey's can still be so damn good sometimes,"^[46]

Accolades

The season was one of the least acclaimed of the series, in terms of awards and nominations. Despite not being nominated for a Primetime Emmy, the show received two Creative Arts Emmy Awards: Outstanding Prosthetic Makeup For A Series, Miniseries, Movie Or A Special for "How Insensitive"^[47] and Outstanding Makeup For A Single-Camera Series (Non-Prosthetic) for "Suicide is Painless".^[48] The season also received a nomination for Outstanding Drama Series at the GLAAD Media Awards.^[49] Wilson was awarded the NAACP Image Award for Outstanding Directing in a Dramatic Series for her directing in "Give Peace a Chance".^[50] The season also ranked at #10 on Movieline's top ten list.^[51]