Long-term care insurance (LTCI) in China may alleviate stress among middle-aged and older adults with disabilities, while potentially influencing their health outcomes and medical services utilization. To evaluate the effect of LTCI on both health outcomes and medical services utilization among middle-aged and older adults, with specific focus on assessing disability’s moderating effect. Using longitudinal data from the China Health and Retirement Longitudinal Study (CHARLS), we employed a time-varying differences-in-differences approach to evaluate the effect of LTCI on both health outcomes and medical services utilization, and to analyze disability’s moderating effect. LTCI effectively increased self-rated health by 0.0907 units and reduced depression levels by 0.4690 units among middle-aged and older adults. The policy also reduced the number of outpatient visits monthly by 0.0705, annual hospitalization probability by 0.0188, and number of hospitalizations by 0.0364. However, disability status attenuated LTCI’s treatment effects, with stronger moderating effect observed in both the IADL subgroup and rural areas. After the implementation of LTCI, improvements in health outcomes and reductions in medical services utilization were observed among middle-aged and older adults. However, there was a critical moderating effect that disability status attenuated LTCI’s treatment effects. These findings reveal disability’s negative moderating role in LTCI’s health effect and the importance of designing policy coverage and carrying out differentiated policy implementation according to disability types and urban-rural distribution.