Abstract: With the deepening of population aging and the increase in medical expenses, the ability of urban and rural residents to pay for medical insurance has weakened, and the financial pressure has been increasing year by year. In order to reduce the personal payment burden, some pilot areas of long-term care insurance adopted a financing method of relying on medical insurance fund transfer during the initial implementation of the system. If this financing method continues, what impact will it have on the financial burden of the medical insurance fund in the future? Based on an actuarial model of medical insurance that includes substitution effects, this paper simulates the operation of long-term care insurance funds and the medical insurance funds in various regions from 2021 to 2050. The results indicate that when the two systems operate independently, the financial burden of medical insurance will significantly increase. If the long-term care insurance relies entirely on medical insurance funds, both the current and cumulative deficits will be advanced by 6 years. If the long-term care insurance has a substitution effect on medical expenses, when the substitution factor for home care subsidies is 2.043, promoting the long-term care insurance nationwide will not have any impact on the sustainability of the medical insurance fund. Therefore, adopting a financing method that relies on the transfer of medical insurance funds during the initial operation of the system will not bring excessive financial burden, but it will help to expand the coverage rate and provide guarantee for the gradual independent operation of the long-term care insurance system.

Key words: long-term care insurance, medical insurance, financial burden, substitution effect