  We determine the full set of coefficients for the completely general 4-loop
gauge and 3-loop Yukawa $ \beta $-functions for the most general renormalizable
four-dimensional theories. Using a complete parametrization of the $ \beta
$-functions, we compare the general form to the specific $ \beta $-functions of
known theories to constrain the unknown coefficients. The Weyl consistency
conditions provide additional constraints, completing the determination.
