While many people are worried about the impact of the Patient Protection and Affordable Care Act's requirement that most Americans have health insurance, the individual health insurance mandate passed by the Massachusetts Legislature in April 2006 has not driven the cost of hospital care higher, according to "The Impact of an Individual Health Insurance Mandate on Hospital And Preventive Care: Evidence From Massachusetts," a new working paper from researchers at the National Bureau of Economic Research (NBER). The researchers examined hospital data to determine how the Massachusetts insurance requirement impacted insurance coverage, healthcare utilization patterns and patient outcomes in the state compared to outcomes in the state before the reform and to outcomes in other states. FierceHealthPayer