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Looking back at the cast of the ABC medical drama
As Grey's Anatomy hits its landmark 300th episode, EW looks back at when each of the current cast members made their debut.
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Meredith Grey (Ellen Pompeo)
The Grey in Grey's Anatomy made her debut in the pilot episode.
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Alex Karev (Justin Chambers)
An original member of the Fab Five group of interns, Alex first appeared in the pilot.
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Miranda Bailey (Chandra Wilson)
Originally known as the Nazi, Bailey appeared in the pilot.
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Richard Webber (James Pickens Jr.)
The original chief at then-Seattle Grace, Webber appeared in the pilot.
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Owen Hunt (Kevin McKidd)
Originally a love interest for Cristina Yang (Sandra Oh), Owen debuted in the season 5 premiere.
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Arizona Robbins (Jessica Capshaw)
Initially a love interest for Callie (Sara Ramirez), Arizona made her debut in the 11th episode of season 5.
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April Kepner (Sara Drew)
A Mercy West transplant, April first appeared in the fifth episode of season 6.
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Jackson Avery (Jesse Williams)
Also hailing from Mercy West, Jackson made his debut in the fifth episode of season 6.
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Amelia Shepherd (Caterina Scorsone)
The younger sister of Derek Shepherd first made her Private Practice debut in the 19th episode of season 3, guesting on Grey's as early as season 7, before moving to the flagship full-time in the 21st episode of season 10.
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Jo Wilson (Camilla Luddington)
Part of a new class of interns, Jo made her debut in the season 9 premiere.
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Maggie Pierce (Kelly McCreary)
Interviewing as a replacement head of cardio, Maggie briefly made a memorable debut in the penultimate episode of season 10 before joining the show full-time in season 11.
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Benjamin Warren (Jason George)
Initially an anesthesiologist from Mercy West, Ben made his debut in the 13th episode of season 6.
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Andrew DeLuca (Giacomo Gianniotti)
An intern initially masquerading as a resident, DeLuca made his debut in the 23rd episode of season 11.