A complete calculation of relativistic and quantum electrodynamic effects t
o order m alpha(6) on the energy of the 2(3)S(1) state in helium is present
ed. The result, beyond the previously known radiative corrections, amounts
to -3.00(1) MHz, and significantly reduces the theoretical uncertainty. The
improved theoretical predictions are compared to the best available experi
mental result for the 2(3)S(1) state.