Objective: By 2014, over 30 million Americans currently lacking health insurance will be able to access health services. While enhancing accessibility to healthcare is a significant step towards reducing health disparities, it is unclear whether access to health services will result in utilization of such services. Previous studies demonstrate that lower socioeconomic status (SES) is a key social determinant of poor health outcomes. The present research examined the potential SES gradient in the utilization of medical services considering healthcare accessibility, and how family support influences healthcare decision-making. Methods: A sample of young Americans with universal access to healthcare services was surveyed to determine whether decisions to visit the doctor for certain symptoms are differed by SES. In a follow-up young adult sample, the bearing of various forms of family support was examined as potential mechanisms that may explain SES differences in seeking healthcare. Results: Among informational, financial, and emotional support, it was found that emotional (how emotionally supportive family is when one is ill) and informational support (how often one consults family for health-related issues) mediated SES and the frequency of health services utilization. Higher SES individuals received more emotional and informational health support from family, which was associated with more immediate healthcare utilization. Conclusion: The findings suggest an explanation for incrementally worse health outcomes for lower SES individuals because of their delay in seeking medical attention. While SES is not a controllable factor, strengthening support networks for health consultation has valuable implications for healthcare promotion and management.