In April 2016, Welteroth was named editor-in-chief of Teen Vogue, making her the second person of African-American heritage in Condé Nast's 107-year history to hold such a title.

[7] She is credited for the notable increase of Teen Vogue coverage of politics and social justice,[8] encouraging readers to become civically engaged, specifically during the 2016 U.S. presidential election.

[9] Under Welteroth's leadership of Teen Vogue's shifting format, the magazine developed its first YouTube channel, featuring content on diverse subjects from campus style to cultural appropriation.

[23] In pursuit of the internship, Welteroth wrote Harriette Cole, then editor in chief, a letter asking for an informational interview, sent her an email, and called her assistant numerous times.

Cole gave Welteroth the chance to assist with a cover shoot for Serena Williams in Los Angeles.

[38] Welteroth expanded the magazine's focus and received recognition for the noticeable increase of content in Teen Vogue on politics and social justice, including critical coverage of the 2016 U.S. presidential election.

[41] The December 2016 cover featured actresses and feminists, Rowan Blanchard and Yara Shahidi on the "Smart Girls" issue.

Blanchard, Shahidi, and Welteroth used Teen Vogue's Facebook account to live stream a discussion about the book in November 2016, allowing the magazine's target audience to engage with political texts by black women that have shaped the continued work of scholar-activists.

[43] The December 2016 issue also featured a conversation between American actress Zendaya Coleman and former First Lady of the United States Michelle Obama on the worldwide education of girls.

During the advance screening of the episode and discussion, Welteroth raised the question, "Is black nepotism just leveling the playing field?

"[48] At Slate, Mark Joseph Stern credited Welteroth for developing Teen Vogue into a publication that "treats teenagers like rounded human beings with agency and intellect".

[49] Stern continues with, "The result is a teen glossy with seriously good political coverage and legal analysis, an outlet for teenagers who—shockingly!

Thanks to their radical push to be unafraid to represent more than just white, heterosexual, cisgender women, Teen Vogue is providing more readers with representation.

[51] Welteroth speaks at varying conferences like the 2017 PATH 40-year celebration and the 2017 Women of Power Summit through Black Enterprise magazine.