This study examined relationships between socioeconomic disadvantage and unmet health care needs among older adults in Korea adjusting for predisposing and health need factors. We examined how older adults' low-income status and working status affect unmet needs for healthcare over time, and how the association varies by reason for unmet needs (i.e. financial or non-financial). We used three waves of data (2009, 2011, 2012) from the Korea Health Panel (KHP) survey and a multinomial logistic mixed model to analyze how low socioeconomic disadvantages affects changes in unmet healthcare needs independently and in combination. Results showed that near-poor elders were more likely to experience increased risk of unmet need due to non-financial constraints over time. When working, near-poor elders risk of unmet healthcare needs due to financial and non-financial factors increases substantially over time. Across societies, different subgroups of older adults may be at risk of unmet healthcare needs, contingent on healthcare policies. Our finding suggests that in Korea, near-poor working elders are the vulnerable subgroup at highest risk of unmet healthcare needs. This finding provides much-needed evidence of heterogeneity of vulnerability in unmet healthcare needs and can be used to design more affordable and accessible programs and services for this group.