  Precision measurements of fundamental quantities have played a key role in
pointing the way forward in developing our understanding of the universe.
Though the enormously successful Standard Model (SM) describes the breadth of
both historical and modern experimental particle physics data, it is
necessarily incomplete. The muon $g-2$ experiment executed at Brookhaven
concluded in 2001 and measured a discrepancy of more than three standard
deviations compared to the Standard Model calculation. Arguably, this remains
the strongest hint of physics beyond the SM. A new initiative at Fermilab is
under construction to improve the experimental accuracy four-fold. The current
status is presented here.
