Although I am not enrolled in the National Health Insurance, the notification of the assessment decision of the National Health Insurance came in my name as the head of the household. why.

The taxpayer of insurance tax is the householder. Therefore, even if the head of the household is not enrolled in the National Health Insurance, if there is a person enrolled in the National Health Insurance in the household, the assessment decision notice will be sent to the head of the household (if the head of the household is enrolled in social insurance, etc. (referred to as the “fictitious householder”).
In addition, calculation of insurance tax becomes only for National Health Insurance member.