The Massachusetts Health Care Reform appears to have been effective at increasing insurance take-up rates. These increases may have come at the cost of lower private insurance coverage. The number of diagnoses per admission was increased by the policy across nearly all MDCs. Understanding the changes in length of stay as a result of the Massachusetts reform, and perhaps the Affordable Care Act, requires MDC-specific analysis. It appears that the most important distinction to make is to differentiate care related to new-born babies and neonates from that related to other diagnostic categories.