Several health reform microsimulation models use synthetic firms to estimate how changes in federal and state policies will affect employers’ offers of health insurance, as well as the price of health insurance for workers and firms. These models typically rely on distinct measures of the average costs of single and dependent coverage, for employees and employers, which do not capture the joint distribution of these costs. Since some firms pay a large share of the premium for single polices but a lower share for dependent coverage, or the reverse, simulation models that do not account for the joint distribution of premium costs may not be sufficient to answer certain policy questions. To address this issue, we developed a method to extract estimates of the joint distribution of employer and employee costs of health insurance coverage from the Medical Expenditure Panel Survey – Insurance Component (MEPS-IC). This paper describes how these distributions were constructed and how they were incorporated into the Urban Institute’s Health Insurance Policy Simulation Model (HIPSM). The estimates presented in this paper and those available in supplementary datasets may be useful for other simulation models that need to utilize information on the joint distribution of single and dependent employee premium contributions.