"Law & Order: Special Victims Units" will inch one season closer to the record of longest-running prime-time drama when it returns for its 18th season next fall, two seasons short of the original "Law & Order" and "Gunsmoke."

NBC renewed the sex crimes procedural on Monday along with freshmen medical drama "Chicago Med," part of Dick Wolf's ever-growing "Chicago" franchise. The network is developing a fourth installment, "Chicago Law," that will air a backdoor pilot as part of an upcoming "Chicago P.D." episode.

NBC previously renewed "Chicago Fire" for a fifth season and "Chicago P.D." for season four, premiering in fall 2016.

Wolf also signed a deal extending his relationship with NBC through 2020. In addition to "SVU" and the "Chicago" shows, the producer is also developing the reality series "Law & Order: You the Jury," where the audience will decide the binding result of a live court case.

"Dick Wolf is without a doubt one of the greatest producers in the history of dramatic television," said Robert Greenblatt, Chairman, NBC Entertainment, in a statement. "The 'Law & Order' legacy would have been enough to set him apart from all the rest, but the Chicago franchise now kicks him into the stratosphere. He has been a defining voice of NBC for over a generation, and he is most welcome at this company forever."

The original "Law & Order" ran for 20 seasons and spun off four shows including "SVU," "Law & Order: Criminal Intent," "Law & Order: Trial by Jury" and "Law & Order: LA."

"Chicago Med" airs on Tuesdays at 9 p.m. and "Law & Order: SVU" airs on Wednesdays at 9 p.m. on NBC.