ObjectiveLong-term care insurance (LTCI) is a widely adopted approach to address the growing long-term care (LTC) needs associated with ageing. Little is known about its effect on unmet LTC needs among different LTC populations in China. This study explored the effect of LTCI pilot programs on unmet LTC needs and their pathways among different LTC need populations in China.MethodsData were derived from the China Health and Retirement Longitudinal Study 2013, 2015, and 2018. Difference-in-Difference methods were used to estimate the impact of LTCI on unmet LTC needs and informal LTC services. According to the degree of ADL or IADL needs, participants were categorised into broad, intermediate, and narrow LTC need populations.ResultsThe unmet LTC needs increased in both broad, intermediate, and narrow LTC need populations, while informal LTC hours received decreased for the intermediate and narrow LTC need populations. Informal LTC was identified as a mediator, contributing to increased unmet LTC needs. With LTCI coverage, heterogeneity analysis showed a direct effect, resulting in a 72.1% reduction in informal LTC hours without an increase in unmet LTC needs. Additionally, a spillover effect led to a 35.7% reduction in informal LTC hours and an average increase of 0.133 unmet needs.ConclusionsWith the inadequate formal LTC services, the LTCI implementation decreased the informal LTC provision and further increased the unmet LTC needs in almost all LTC need populations. Only for individuals with severe disabilities LTCI effectively substituted the informal LTC provided by families. The government needs to improve the quality of formal LTC services to avoid increasing unmet LTC needs.