See schedule OAS a proud member of medstar health, medstar ST. MARY's hospital's (medstar ST. MARY's) mission is to uphold its tradition of caring by continuously promoting, maintaining, and improving health through education and service while assuring quality care, patient safety and fiscal integrity. Medstar ST. MARY's is located in leonardtown, maryland, in the southern region. In fiscal year 2023, MSMH had 7,214 inpatient admissions and 124,547 outpatient visits including 38,360 emergency visits.