MonoMAC syndrome is characterized by monocytopenia with susceptibility to nontuberculous mycobacterial infections. First recognized in 2011, it is caused by GATA2 mutations and can manifest as disseminated mycobacterial, fungal, and viral infections. While mortality rates for this disorder have been high, it has recently been successfully treated with haploidentical allogeneic stem cell transplant. Since approximately one third of patients may have rheumatologic symptoms, such as erythema nodosum, panniculitis, or arthralgias, rheumatologists may expect to encounter this newly described entity with increasing frequency.