In Germany, employees are generally obliged to participate in the public health insurance system, where coverage is universal, co-payments and deductables are moderate, and premia are based on income.

However, they may buy private insurance instead if their income exceeds the compulsory insurance threshold.

Here, premia are based on age and health, individuals may choose to what extent they are covered, and deductables and co-payments are common.

In this paper we estimate the effect of private insurance coverage on the number of doctor visits and self-assessed health.

Variation in income around the compulsory insurance threshold provides a natural experiment that we exploit to control for selection into private insurance.

We document that income is measured with error and suggest an approach to take this into account.

We find negative effects of private insurance coverage on the number of doctor visits and positive effects on health.