Special education services provided in U.S. schools should be designed to enable students with disabilities (SWD) to make “appropriately ambitious” educational progress (Endrew F., 2017). Yet the field lacks consensus on whether business-as-usual (BAU) special education services effectively support outcomes for SWD. We conducted a moderated multilevel multivariate meta-analysis of 40 studies and 1,721 effect sizes from more than 14 million participants to evaluate the effectiveness of BAU special education services. Effects ranged from null-to-positive (z = -0.07 to 0.12) for achievement and negative-to-null (z = -0.13 to -0.01) for behavior. We observed positive outcomes for educational attainment including graduation outcomes (z = 0.12 to 0.24) and postsecondary outcomes (z = 0.10 to 0.23), as well as for other outcomes (z = 0.21 to 0.38). Studies that used a more rigorous research design or comparison condition reported more positive effects across outcomes. Additional casual work is needed in this field.