Grey's Anatomy season 10 will include more screen time for four Grey Sloan Memorial interns, that where signed on as series regulars recently.

Recurring stars Camilla Luddington (Jo Wilson), Gaius Charles (Shane Ross), Jerrika Hinton (Stephanie Edwards) and Tessa Ferrer (Leah Murphy) have all been promoted to series regulars for the upcoming season of the medical drama, ABC confirmed to HuffPost TV.

All four actors joined the series at the start of season 9, as well as Tina Majorino. The actress, who plays Heather Brooks on Grey's Anatomy,joined the Veronica Mars movie this month, reprising her role as Mac. She is also signed on as a series regular for TNT's Legends, which will debut in 2014. Because of her other commitments, an ABC rep said it is unknown at time of publication whether she has a future on season 10 of Grey's Anatomy.

 In season 9 of the ABC series, Stephanie was a love interest for Jackson Avery (Jesse Williams) following his breakup with April Kepner (Sarah Drew); Brooks and Ross were competing for Dr. Shepherd's (Patrick Dempsey) attention but Ross ended up helping save Meredith's (Ellen Pompeo) life in the season finale; and Leah almost lost her job after Dr. Miranda Bailey's (Chandra Wilson) surgical error caused a Center for Disease Control investigation at the hospital

Jo looked to Alex Karev (Justin Chambers) for help after getting abused by her boyfriend. The season ended with the two of them finally expressing their love for one another and kissing.

The fate of actress Hilarie Burton, who appeared at the end of season 9 as Dr. Lauren Boswell, has also yet to be determined, according toThe Hollywood Reporter. In the season 9 finale she had an affair with doctor Arizona Robbins (Jessica Capshaw), coming in between the latter's marriage with Callie Torres (Sara Ramirez).

The same unknown fate can be said for James Pickens Jr., who plays former hospital chief Richard Webber. He was last seen unconscious in the flooded basement of Grey Sloan Memorial, electrocuted after the power came back on in the wake of the storm at the end of the season 9 finale.

"Hopefully that's not going to happen, but we don't know," Kevin McKidd (Dr. Owen Hunt) told TV Guide in May of Richard's possible death. "If there's a chance to save Richard, you're going to have every doctor at Grey Sloan Memorial clamoring over each other to get in that OR to save him."

The show's executive producer, Shonda Rhimes, did not address Richard's potential death directly, but told Entertainment Weekly in May that we "will see Jim Pickens again."

ABC renewed Grey's Anatomy for a 10th season in May. The new season airs in the fall, Thursdays on ABC at 9/8 p.m. Central.