Even their dog, Daisy, is getting into the act, E! Online reports.
And Lachey is getting his own solo show while sister-in-law Ashlee Simpson has been signed for a second season of her reality trip.
MTV said in a statement Lachey and Simpson have a tremendous connection with viewers.
Word of the renewals comes at the same time tabloids are questioning the state of their marriage and Ashlee's bolting off the "Saturday Night Live" set.
Lachey's and Simpson's ABC special Wednesday scored a solid 12.4 million viewers.