e14019 Background: Meningeal melanomatosis (MM) is a rare and aggressive central nervous system neoplasm that normally occurs in the leptomeningeal melanocytes. Meningeal melanomatosis represents only 0.06% to 0.1% of all primary brain tumors, but it is accompanied with a very poor prognosis with data showing a mean survival of 10 weeks after diagnosis. Despite intrathecal chemotherapy treatment, only a modest positive effect on survival was observed. Limited research has been done. In this study, demographic factors in patients diagnosed with MM from the National Cancer Database (NCDB) were analyzed to elucidate potentially valuable insights regarding its epidemiology. Methods: A retrospective cohort study using data collected between 2004–2020 from the NCDB included 137 patients with a histologically confirmed diagnosis of MN. The descriptive analysis included an examination of demographic factors such as sex, age, race, Hispanic status, insurance coverage, type of medical facility, and Charleson-Deyo score. Primary site was also analyzed. Results: A total of 137 patients were identified with a diagnosis of MM between 2004 – 2020. The most common primary sites of MM were the meninges, not otherwise specified (NOS) (43.8%), spinal meninges (29.2%) and cerebral meninges (19.0%). In the dataset, 50.4% of diagnosed patients were male. The average age of diagnosis was 51.4 years (SD = 21.5, range = 0 – 90 years). The majority of the individuals (73.7%) had a Charlson-Deyo comorbidity score of 0. Most of the individuals diagnosed with MM were non-Hispanic (83.9%) and 87.6% of patients with diagnosed MM were White. Among the 115 patients with available data for median household income, 37.4% were in the top income quartile. A greater proportion of patients, 54.7%, had private insurance compared to those without insurance or those insured through Medicare or Medicaid. The majority of patients resided in metropolitan counties with a population exceeding 250,000 (71.8%) For patients with documented treatment facility type (N = 99), 56.6% of patients were treated in an academic/research program. Conclusions: This first NCDB analysis fills a crucial void in the existing knowledge on MM. MM affected males and females equally, contrary to published literature which suggested a slight predominance in males. The most common primary sites of diagnosis were the meninges NOS, spinal meninges and cerebral meninges, which supports findings in the literature. This is a novel description of the socioeconomic factors of MM patients in the literature, showing that these patients tend to have higher incomes and reside in densely populated metropolitan areas, and are more likely to receive treatment in an academic medical facility. Additional research is imperative to elucidate the influence of demographic and socioeconomic factors on the diagnosis, treatment options, and overall survival outcomes for patients with MM.