OBJECTIVES: The objective of this analysis was to describe hospital-based resource utilization among a population of patients with Multiple Sclerosis (MS) in the United States, including both inpatient and outpatient hospital services. METHODS: A retrospective cohort analysis was conducted on a cross-section of 88,679 unique patients using hospital-based inpatient and outpatient services between 2013 and 2014 with a diagnosis of MS. Multivariate logistic regression was used to evaluate drivers of resource utilization define as total patient visits and length of stay (LOS) controlling for patient and hospital characteristics as well as patient comorbidities. RESULTS: The mean age for MS patients was 49.9 years with 76.0% female.  Utilization was highest in the OP setting (88.8%) with 68.3% of OP visits having a primary diagnosis of MS.  The primary diagnosis for IP admissions varied with the most common including infectious and parasitic diseases (6.6%), cerebrovascular disease (6.2%), chronic obstructive pulmonary disease (5.5%), heart failure (5.2%) and ischemic heart disease (5.2%). MS patients were primarily treated in large (89.4%) and teaching (64.7%) hospitals. The mean Charlson comorbidity score was 0.86 (SD =1.6) with chronic pulmonary disease (11.5%), diabetes (11.4%), plegia (4.1%), and malignancy/tumor (4.9%) as the most common comorbidities. The population averaged 2.8 (SD=6.2) total, 2.4 (SD=4.1) outpatient, and 0.38 (SD=0.78) inpatient visits per patient. The overall average LOS was 3.6 (SD=31.2) days. Congestive heart failure (RR = 1.26, CI 1.13-1.41), hemiplegia or paraplegia (RR = 1.59, CI 1.28-1.96), renal disease (RR = 1.36, CI 1.09-1.68), and dementia (RR = 1.22, CI 1.05–1.42) were associated with increased hospital LOS. CONCLUSIONS: MS is primarily managed in the community or OP setting.  As MS-related complications develop patients are admitted for IP services.  Once hospitalized complications and comorbid conditions contribute to increased resource utilization as measured by increased LOS.