First episode (2005): "A Hard Day's Night" (Season 1, Episode 1)

Last episode (2010): "I Like You So Much Better When You're Naked" (Season 6, Episode 12)

What she's up to now (2020): After leaving Grey's, Katherine starred in a number of movies, including Life as We Know It and One for the Money. She also joined the cast of Suits for the final two seasons. In 2020 she's expected to star in Netflix's Firefly Lane opposite Sarah Chalke.