In this study the tensile properties of additively manufactured Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS) and Silicon Carbide (SiC) particulate filled PLA composites were assessed after aging for 4.5 months at 50°C in distilled water. The maximum moisture gain in PLA was about 16% by weight, and ABS gained 0.65%. In PLA/SiC composites, the weight gain due to moisture absorption was inversely proportional to the weight percentage of SiC loading. The PLA specimens degraded completely during aging without measurable residual strength. While the addition of SiC to PLA increased the room temperature tensile strength at lower volume fractions of SiC, the degradation of aged strength was similar to that of the pure PLA. The PLA/SiC composites had no measurable strength after aging. The ABS specimens retained their strength and failure strain after aging.