this talk is about a theory of local newforms for irreducible, admissible representations of the group $gsp(4,f)$, where $f$ is a non-archimedean local field. we will present a joint work with brooks roberts, where we proved the existence of a local newform theory analogous to casselman's theory for $gl(2,f)$. a key feature of our theory is to consider fixed vectors under a family of open-compact subgroups called the paramodular groups. local newforms provide a link between classical modular forms and automorphic representations. our theory therefore has applications to siegel modular forms of degree $2$; this will be discussed in a talk by brooks roberts.