"Now Or Never" is the twenty-fourth episode of the fifth season of Grey's Anatomy and the 102nd produced episode of the series. It is also the 133rd produced episode of the Grey's Anatomy franchise. It was broadcast on May 14, 2009.
George delivers news that send shockwaves around the hospital while Seattle Grace must come together to save the life of a trauma victim, but Meredith makes a revelation that no one could see coming. The doctors all anxiously wait for Izzie's recovery from her surgery. George's decision brings about a difference of opinion between Callie and Arizona while Bailey faces a difficult choice when her husband makes her choose between their marriage or her peads fellowship. Cristina makes a choice about her future with Owen.
- "Doctors spend a lot of time focused on the future; planning, working toward it. But at some point you start to realize your life is happening now. Not after med school, not after residency, right now. This is it. It's here. Blink and you'll miss it."
- "Did you say it? I love you. I don't ever want to live without you. You changed my life. Did you say it? Make a plan, set a goal, work toward it but every now and then look around. Drink it in. Because this is it. It might all be gone tomorrow."
- "All Love" - Ingrid Michaelson
- "The Battle" - Missy Higgins
- "Flashdance... What A Feeling" - Hollywood, Mon Amour feat. Yael Naim
- "Off I Go" - Greg Laswell
This episodes' title references the album Now Or Never, originally sung by Three Days Grace
- This episode is the first season finale to feature a full opening and closing voiceover since the Season One finale "Who's Zoomin' Who?"