X0101 EFFECT 33 LIVE 2010-05-06 0000898745-10-000277 485APOS 0000898745 PRINCIPAL FUNDS INC 033-59474 S000014245 Short-Term Income Fund C000090493 Class J Shares S000014245 Short-Term Income Fund C000090494 Class R-1 Shares S000014245 Short-Term Income Fund C000090495 Class R-2 Shares S000014245 Short-Term Income Fund C000090496 Class R-3 Shares S000014245 Short-Term Income Fund C000090497 Class R-4 Shares S000014245 Short-Term Income Fund C000090498 Class R-5 Shares