Myasthenia gravis (MG) is a rare neuromuscular disorder with geographically variable prevalence and incidence rates. A global trend of increasing prevalence of MG has been observed in the last few decades, and this study aimed to assess the current prevalence and incidence rates of MG in the United States. Data were extracted from the Clarivate Real-World Data Repository (2016-2021), a US claims and electronic health records database. The prevalence and incidence of MG were calculated for the year 2021 for males and females who were <2, 2-5, 6-11, 12-17, 18-49, 50-64, and ≥65 years of age, using population estimates from the US Census. The diagnosed prevalence and incidence of MG in the United States in 2021 were calculated to be 37.0 per 100,000 persons and 3.1 per 100,000 persons, respectively. While the incidence and prevalence of MG increased with age in both men and women, higher prevalence and incidence of MG were observed in younger women (<50 years) compared with men of matching age, and in older men (≥65 years) compared with women of the same age group. The updated prevalence and incidence of MG in the United States in 2021 are higher than previous reports from the 1980s and early 2000s, following a global trend of increased prevalence and incidence for this disorder in the last few decades.