Amy Robach is moving off ABC’s “Good Morning America” to take over as co-anchor of the prime-time newsmagazine “20/20.”

ABC News President James Goldston announced today that Robach will replace Elizabeth Vargas, who announced late last year that she would leave “20/20” this spring.

Vargas, whose co-anchored “20/20” for 14 years, is joining A+E Network to become the host of the cable network’s “A+E Investigates” series. She will also develop and produce other nonfiction shows for parent company A+E Networks.

Robach, 45, will co-anchor “20/20” with David Muir, the anchor of “ABC World News Tonight.”

Robach joined ABC News in 2012 after time as a national correspondent at NBC and MSNBC. She became the news anchor on “GMA” in 2014.

Robach became a national story herself after a mammogram she had on “GMA” revealed that she had breast cancer. She wrote a bestselling book about her ordeal.

Goldston said Robach will continue to report for “GMA” during coverage of major news stories.

The personnel change is the second in recent weeks for “GMA.” Longtime regular Lara Spencer has reduced her role to three days a week in order to devote more time to the programs she hosts for cable network HGTV.

“Good Morning America” has regained its status as the most-watched network morning program after NBC’s “Today” scored a run of weekly wins while reporting from Pyeongchang, South Korea, for the 2018 Winter Olympics. For the 2017-18 TV season, “GMA” is averaging 4.292 million viewers, giving it a razor-thin lead over “Today,” which has 4.290 million viewers. “CBS This Morning” has about 3.4 million viewers.

In terms of top on-camera personnel, “GMA” has been the most stable of the three broadcast network morning shows. It has kept its core anchor team of George Stephanopoulos, Robin Roberts and Michael Strahan intact while its broadcast competitors have seen major personnel departures.

Matt Lauer was dropped from “Today” on Nov. 29 amid charges of inappropriate sexual behavior with an NBC employee. “CBS This Morning” co-anchor Charlie Rose was fired Nov. 21 after a report that he had sexually harassed women who worked on his now-canceled PBS talk show.