From 1973 through 2016, Mueller was the only FBI Director to be appointed to more than one
term. P.L. 112-24, enacted on July 26, 2011, allowed the incumbent Director to be nominated for, and appointed to, an additional two-year term. After the bill was signed, Mueller was nominated for this second term by President Barack Obama, and he was confirmed the following day by a vote of 100-0. Mueller’s two-year term expired on September 4, 2013.
https://fas.org/sgp/crs/misc/R44842.pdf