<p>Earthworms promote litter incorporation into soil, potentially increasing soil organic carbon (SOC) stocks. However, they may also stimulate native SOC mineralization through priming, complicating assessments of their net impact on carbon sequestration. To disentangle these opposing pathways, we conducted an incubation experiment in soils with contrasting management histories using dual-isotope labeled litter, which allowed us to distinguish litter-derived carbon from native SOC in both soil and CO₂ emissions. We show that earthworms consistently enhanced litter incorporation into the soil while increasing total soil CO₂ emissions. However, the earthworm-induced increase in respired CO₂ was entirely derived from the added litter, not native SOC, and the formation efficiency of new SOC was up to ninefold higher in the presence vs. absence of earthworms. Therefore, increased heterotrophic respiration in the presence of earthworms does not translate into lower SOC contents in mineral soil. Given that these effects were consistent across contrasting management systems, fostering earthworm activity may support SOC sequestration across agroecosystems and help mitigate climate change.</p>