This paper presents a stochastic overlapping generations model with endogenous health investment to study the transition from the existing hybrid health insurance system in Germany towards a uniform system, financed by either funded or unfunded premiums or payroll taxes.Our simulation results highlight the insurance properties of payroll taxes, but also their cost in terms of labor supply distortions and moral hazard. We find that compulsory deductibles decrease aggregate welfare in Germany, although they reduce moral hazard and increase private health investment. Reform models with premiums also induce precautionary behavior and increase labor supply, but at the same time increase exposure to productivity risk. Since the introduction of a funded system is costly for transitional cohorts, unfunded premiums provide the highest efficiency gains in our framework.