The National Institute for Health and Disability Insurance (NIHDI) is a federal public body of social security in Belgium.

Under the authority of the Belgian federal minister of Social Affairs and Public Health, it is responsible for administering the country's compulsory national schemes for health insurance and disability benefits, and manages a compensation fund for medical accidents.

The institute was founded by the law of 9 August 1963, establishing and organizing a scheme for compulsory insurance for medical treatment and benefits, which came into force on 1 January 1964.

[1] The law of 1963 has since been replaced by the law of 14 July 1994 regarding the compulsory insurance for medical treatment and benefits coordinated on 14 July 1994.

[2] The institute's health and disability insurance budget for 2017 amounted to more than 37 billion euros.