Attention has recently been paid to light-front Tamm-Dancoff field theory in 1 + 1 dimensions, including the proposition of a sector-dependent renormalization procedure. We extend this formalism to 3 + 1 dimensions, and examine a two-fermion system using light-front field theory in the lowest nontrivial Tamm-Dancoff approximation. It is found that the extension to 3+ 1 dimensions results in an integral equation with a kernel which does not decrease rapidly enough to admit solutions for L j = O states.PACS number(s1: 11.1O.St