Abstract Inborn errors of immunity may present with susceptibility to coccidioidomycosis. This is especially so in disorders impairing the interferon-γ and interleukin 12 signaling axis. We describe the first case of cytidine nucleotide triphosphate synthetase 1 (CTPS1) deficiency, a combined immunodeficiency impairing lymphocyte proliferation, presenting with coccidioidomycosis.