We report on the status of the calculation of the massive Wilson coefficients and operator matrix elements
for deep-inelastic scatterung to three-loop order. We discuss both the unpolarized and the polarized case,
for which all the single-mass and nearly all two-mass contributions have been calculated. Numerical
results on the structure function $F_2(x,Q^2)$ are presented. In the polarized case, we work in the Larin
scheme and refer to parton distirbution functions in this scheme. Furthermore, results on the three-loop
variable flavor number scheme are presented.