Longtime MTV executive Lauren Dolgen is leaving the company, after 19 years, Variety has confirmed.

Dolgen is stepping down from her position of head of reality programming and EVP of series development. Her position will not be replaced.

Among her many responsibilities in her near two decades at MTV, Dolgen shepherded the long-running “16 and Pregnant” and “Teen Mom” franchises, plus many specials and events.

Dolgen was promoted in March of last year to oversee all of MTV’s unscripted programming, following many East Coast layoffs at the network. Previously, she was head of West Coast reality programming, before taking over all of MTV’s unscripted.

Dolgen’s exit comes shortly after Michael Klein joined MTV as EVP of original content, who joined the network, after Susanne Daniels left to join YouTube.

The reshuffling at MTV is a piece of the large shakeups at Viacom with Dolmen becoming the latest exec to depart the company. One week ago, Nickelodeon president Russell Hicks stepped down from his position, after 18 years with the company. Comedy Central also recently saw a shuffle up top. VHI and TV Land have also endured recent exec changes.

Here is the internal MTV memo, regarding Lauren Dolgen’s departure:

Lauren Dolgen, our Head of Reality Programming and owner of an incredible run of hits in her nearly 20-year career at MTV, is leaving the company. You can trace Lauren’s career in the history of the network over the past two decades, and as an exec she represents the best of the brand – smart, funny, irreverent, full of ideas, and an absolute junkie for culture and content. She’s been behind some of the most kinetic hits in MTV’s history, cutting her teeth on the seminal “Jackass” and then developing many of its spiritual successors – “Rob Dyrdek’s Fantasy Factory,” “Rob and Big,” “Viva La Bam,” “Wild Boyz,” and “Buckwild.” And, of course, “Ridiculousness,” which eight seasons in remains a strong pillar of our schedule. So many of those shows point to what MTV can and should do best – series that may not be specifically music, but have music, whether it’s skate punk or hip hop, clearly in their DNA. Her work in engineering the successful run of “America’s Best Dance Crew;” reinventing “The Real World,” and launching “Are You The One?” speak to the versatility she’s brought to the brand. It’s a track record I admired long before I walked in the door.

And then there’s the “16 and Pregnant”/”Teen Mom” franchise, an unequivocal cultural phenomenon spawned from Lauren’s simple idea to explore the challenges and triumphs of very young mothers. “Teen Mom” has been a top-five MTV series every year since it launched in 2009, and ratings aren’t even the most powerful measure of its impact. Studies have credited the franchise with driving up to one-third of the overall decline in teen pregnancy – a staggering statistic. “Teen Mom” alone puts Lauren in the hall of fame.

Lauren has been discussing the next chapter in her career with Sean for a few months now and I want to thank her for helping with the transition – and for her work in helping jumpstart the development pipeline. I look forward to digging in with the team and working to push this brand forward.

I hope you’ll join me in thanking Lauren for her brilliant career with MTV and wishing her the very best of luck.