'Grey's Anatomy' is back with Season 20: How the medical drama keeps reinventing itself after nearly 2 decades on the air

Grey’s Anatomy is going back to the beginning.

The longest-running medical drama prepares to launch its landmark 20th season on March 14, capping off a 10-month wait for viewers due to the writers and actors strikes. The ABC series is honoring the past as it charts a path forward amid years of cast departures, including a limited presence for star and executive producer Ellen Pompeo and several creative resets.

Despite changes in front of and behind the camera, Grey’s Anatomy remains ABC’s crown jewel in primetime and is still one of network television’s most consistent ratings performers — an increasingly difficult feat to accomplish as it reaches rarefied TV air.

According to Nielsen's streaming charts, Grey’s Anatomy is consistently among the top-streamed TV shows on streaming platforms. Last season averaged 10.7 million total viewers with delayed viewing on linear and digital platforms, making it ABC's No. 1 entertainment series. It is also one of the most profitable franchises for Disney, reportedly generating $3 billion.

It’s no wonder the new season of Grey’s Anatomy, which is overseen by new showrunner Meg Marinis — whose history with the show dates to Season 3 — will be a celebratory one.

“I'm a huge fan of the show, as well as working on it — and I have been since it came on in the very beginning,” Marinis tells Yahoo Entertainment. “No one gets 20 seasons and I thought we needed to honor the show that's gotten us here.”

Created by Shonda Rhimes, Grey’s Anatomy debuted as a midseason replacement in spring 2005 with a star-filled ensemble led by Pompeo, Sandra Oh, Patrick Dempsey, Katherine Heigl, Justin Chambers, T.R. Knight, Chandra Wilson and James Pickens Jr.

The series quickly skyrocketed in popularity and became a pop culture phenomenon. Its most-watched episode is the explosive post-Super Bowl installment in 2006, which boasted 37.8 million viewers.

While many of its original cast members have left (some have returned for memorable arcs) and new characters introduced, the show’s formula has stayed the same. Grey’s Anatomy chronicles the complicated personal and professional lives of interns, residents and attending physicians at Grey Sloan Memorial Hospital, formerly Seattle Grace.

In addition to soapy romantic entanglements, the show keeps a captive audience through a mix of weird medical cases (a man with tree hands in Season 7), bizarre emergencies (a pregnant man in Season 2) and life-or-death stakes for its doctors (Meredith holding a bomb inside a patient in Season 2).

Season 20 is a callback to the classic Grey’s days, Marinis says, a recognition of the iconic characters that have passed through the hospital halls, unusual patients and two decades of history. Parallels to early seasons and key characters who have long been gone are sprinkled throughout in the nostalgic premiere episode, which marks the franchise’s 421st hour. (The medical emergency at the heart of the Season 20 opener, for instance, involves an AI-powered self-driving vehicle.)

“We haven't been on the air for so long, so I want to give people old Grey’s and I want to give them a part of Grey’s that has everything,” Marinis explains, describing the new season as “a reset.” “Your heart's pounding because of the action, I want rom-com stuff, I want things that are hilarious, I want things that make you cry. I wanted to get every emotion that Grey's is known for giving into one episode.

“I wanted to be like, ‘Fans, we're here and we're back. We're still who you love,’” she says. “And also the idea of honoring where our characters have been. Even though we may have seen certain people in certain roles, they come to it with a different experience because it's 20 years later.”

The new season picks up in the immediate aftermath of the Season 19 finale following Teddy’s (Kim Raver) operating room collapse just as she’s about to perform potentially life-saving surgery on a patient, Sam Sutton (guest star Sam Page). Under intense time pressure, the interns decide to move forward with his surgery, the ramifications of which will bear out in the premiere.

Other lingering finale threads are also left in limbo, most notably the status of Meredith Grey’s research study, now in danger of losing funding after she publicly shares her radical new Alzheimer’s theory.

“One of the themes that we have been working with is this idea of ‘back to basics,’” Marinis says. “Because so many characters had so many heavy moments at the end of the finale of last season, they have a long road to come back from that — and reflecting on how one comes back from big things.

“I love mess because it’s fun to undo it: ‘Let's tie all the character stories into huge knots.’ I love when fans are like, ‘How are they going to come back?’ It was such high adrenaline and high emotion that we didn't want to skip a moment. Even though we answer a lot of things in the premiere, we're still going to be unpacking what everyone went through in last year’s finale [throughout the season].”

Familiar faces from the past, such as Jessica Capshaw, who portrayed Dr. Arizona Robbins for 10 seasons, will return in the April 4 episode nearly six years after her departure. The last time audiences saw the character in 2018, Arizona decided to move to New York with her daughter to reunite with another Grey’s Anatomy alum, Dr. Callie Torres (portrayed by Sara Ramirez).

“When Arizona came up, it was pitched in conjunction with a story that was perfect for the character and so the stars did align where it worked out with her schedule,” Marinis teases. “We have an open-door policy — we have people come and go — and it’s a way to honor where the show has been by seeing old characters come back and interact with new characters. The hospital’s changed quite a bit since she’s been here.”

Pompeo’s lightened workload on Grey’s Anatomy continues in Season 20, where she’s expected to appear in at least four episodes. The premiere sets in motion a season-long story arc involving Amelia (Caterina Scorsone) that carves out a way for Meredith to organically weave in and out of the show.

“In my mind, offscreen, everyone still texts and talks. Meredith also works for the Catherine Fox Foundation, so I don’t feel like we’ll ever not be able to find a way to thread her through,” Marinis explains. “But the premiere does introduce a way of how that’s going to work.”

At the end of the day, the producer believes “the essence” of Grey’s Anatomy is still firmly intact.

“The heart of the show — what Shonda established 20 years ago — that's still there. Even though Meredith isn't in every single episode, her voice-over is and it still feels like we have Meredith here all the time," Marinis says.

Grey’s Anatomy premieres March 14 at 9 p.m. ET on ABC.