“Grey’s Anatomy” debuts its 332nd episode today, bypassing “ER” to become the longest-running prime time medical drama in U.S. TV history. Now in its 15th season, the show created by Shonda Rhimes still commands some of the highest advertising rates in prime time, typically pulling in a weekly audience of more than 7 million viewers.

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Clarification (Feb. 28, 2019): The text has been updated to reflect that “Grey’s Anatomy” is the longest-running prime time medical drama in U.S. TV history.