Environmental hazards and heightened neighborhood social vulnerability coexist and disproportionately affect minoritized populations. We investigated associations between adverse environmental burden concentrated in areas with high social vulnerability with care fragmentation (missed appointments, Emergency Department (ED) visits and hospitalizations) and social needs (e.g., food and housing insecurity) among individuals with rheumatic conditions. We identified adults receiving care in a Massachusetts multihospital system with >2 rheumatic disease codes and complete street addresses. Geocoded addresses were linked to the CDC/ATSDR Social-Environmental Ranking (SER), which combines census tract social vulnerability variables (e.g., socioeconomic status) with environmental hazards (e.g., air and water pollution). Social needs were from self-reported surveys. Multilevel, multinomial regression models estimated associations between SER quartiles, care fragmentation, and social need burden, accounting for demographics and comorbidities. Among 16,856 individuals with rheumatic conditions, 70% were female, 6% were Black, 82% were White, and 7% resided in the highest combined social vulnerability and environmental burden (SER Quartile 4) areas. Among 7,083 with social needs data, 19% experienced >1 challenge. Individuals in SER Quartile 4 areas (vs. Quartile 1), had 2.02 (95% CI 1.67-2.46) times greater odds of >4 care fragmentation occurrences (vs. 0) and 2.37 (95% CI 1.73-3.25) times greater odds of >2 social needs (vs. 0). Residence in areas of high combined adverse environmental burden and social vulnerability was associated with significantly greater odds of care fragmentation and social needs. Addressing structural factors and emerging environmental threats contributing to these adverse exposures is essential to reduce rheumatic disease care inequities.