  The Fermilab Muon $g-2$ experiment measures the muon anomalous magnetic
moment with high precision. Together with recent improvements on the theory
front, the first results of the experiment confirm the long-standing
discrepancy between the experimental measurements and the Standard Model
predictions. The observed value of $a_\mu({\rm FNAL}) = 116\,592\,040(54)
\times 10^{-11} ~ (\text{0.46\,ppm})$, combined with the previous experimental
measurement, results in a discrepancy of $ (251 \pm 59)\times 10^{-11}$ with
the theoretical prediction, corresponding to $4.2 ~\sigma$. This note presents
the first results, the current status and the future prospects of the Muon g-2
experiment at Fermilab.
