This chapter examines the spectral version of the well-known Ulam reconstruction conjecture, focusing on whether the characteristic polynomial of the adjacency matrix of a signed graph with at least three vertices is uniquely determined by the collection of characteristic polynomials of its vertex-deleted subgraphs. In the setting of signed graphs, a simple counterexample already exists: a pair of signed cycles on the same vertex set, with exactly one of them balanced. Beyond this instance, no additional counterexamples are known. We establish a sequence of structural properties that are reconstructible from the polynomial deck and identify several classes of signed graphs for which the characteristic polynomial is uniquely reconstructible. These classes include trees, unicyclic signed graphs (other than cycles) and signed graphs whose spectrum is bounded below by −2, among others. We also present numerous specific results concerning additional graph families.