Injection molding is a widely used mass-production technology, accounting for approximately 35% of all polymer production by weight. Although it is traditionally linked to high-volume manufacturing, there is an increasing demand for cost-effective solutions for low-to-medium-volume production runs. Consequently, additive manufacturing has been gaining attraction in addressing these needs. This technology offers a novel approach that changes the environmental impact across the entire product life cycle, enhancing sustainability potential. By producing items layer by layer, additive manufacturing reduces waste by creating products precisely as needed. As this technology becomes more prevalent in the manufacturing industry, quantifying its environmental impact will further support its adoption. Therefore, this study explores the environmental implications and energy analysis of using additive manufacturing for low-volume production. The study focuses on four (4) mold inserts (MIs) made using stereolithography apparatus, namely High-Temperature Resin Mold Insert, in both solid and hollow designs (HTS, HTH), and Rigid 10 k Mold Insert, also in solid and hollow designs (RS, RH), within a cradle-to-gate system boundary. Results show that fossil resource scarcity, for all four MIs, has the highest environmental implications, followed by terrestrial ecotoxicity and human carcinogenic toxicity. Meanwhile, for cumulative energy demand, there is no drastic increase in the overall energy consumption. RH had the lowest at 591.59 MJ, followed by RS, HTH, and HTS at 600.14, 601.33, and 609.59, respectively. Overall, 95% of the energy consumption is allocated from non-renewable fossil sources.