  We present free field realizations for the associated vertex operator
algebras of a number of four-dimensional $\mathcal{N}=2$ superconformal field
theories. Our constructions utilize an exceptionally small set of chiral bosons
whose number matches the complex dimensionality of the Higgs branch of the
superconformal field theory. In the case of theories whose Higgs branches
support additional degrees of freedom (free vector multiplets or decoupled
interacting SCFTs), the corresponding "free field realizations" include
additional ingredients: symplectic fermions in the case of vector multiplets
and a $C_2$ co-finite VOA in the case of a residual interacting SCFT. The
resulting picture is that the associated VOA can be constructed from the Higgs
branch effective theory via free field realization. Our constructions also
provide a natural realization of the $R$-filtration of the associated VOA.
