Introduction: Systemic Mastocytosis (SM) is a rare disorder in which mast cells pathologically accumulate within tissue. The mast cells can be limited to the skin, or they can be systemic and involve extracutaneous tissues. One subtype of systemic mastocytosis (SM) is called indolent systemic mastocytosis, which is considered a less aggressive form of the disease, compared to advanced systemic mastocytosis which is considered to have organ impairment due to mast cell infiltration. Multi-kinase inhibitors such as Midostaurin and Imatinib are often used in the treatment of advanced SM or indolent SM that is refractory to conservative symptomatic treatment, but currently Avapritinib is reserved for treatment of advanced SM. Here is a case of an indolent SM responding to treatment with lower dose Avapritinib.