A comprehensive review of 27 separate studies forecasting how the new health care law will affect employer-sponsored health coverage finds that predictions vary widely depending on the type of study conducted. The Government Accountability Office (GAO) report – Patient Protection and Affordable Care Act; Estimates of the Effect on the Prevalence of Employer-Sponsored Health Coverage (pdf) – examined health care studies issued between January 1, 2009 and March 30, 2012. Five of these studies were considered microsimulation models. These types of studies incorporated a number of Affordable Care Act (ACA) provisions and were based on multiple data sets and assumptions. Three studies were based on other types of analytic models. The remaining 19 studies were employer surveys, which are based on employer responses to questions.

In reviewing these studies, the GAO examined estimates of how the health care law will affect employer-sponsored coverage, various factors that might have caused variation in these estimates, how the estimates vary by types of employers and employees, and what steps employers are considering taking in response to the law’s implementation. In general, the GAO report determined that the microsimulation studies predicted little change in the provision of employer-sponsored coverage when the majority of ACA’s provisions take effect in 2014. In contrast, findings reached by the employer surveys varied dramatically.

Specifically, the microsimulation studies indicated that anywhere from 2.5 percent fewer individuals to 2.7 additional individuals will be covered by employer-sponsored health coverage in the near future. These studies also looked at how the individual mandate would impact employer-sponsored coverage. Generally, these studies found that more people would have employer-sponsored coverage with the mandate than without. The report notes that differences in key assumptions might have caused some of the variations in the microsimulation estimates.

The employer surveys, however, by and large focused on the percentage of employers that planned to drop coverage beginning in 2014. The percentage of employers that planned to do so ranged from 2 to 20 %. A number of these surveys indicated that the smaller the employer, the greater the chance of abandoning coverage. The GAO emphasized that because these surveys typically included responses from employers that were already offering their employees health coverage, they did not reflect the number of employers that might start offering coverage as a result of the health care law. The GAO emphasized also that employer surveys are more limited in their predictive power, as they are based on individual knowledge and perspective.

Highlights of the GAO report can be found here.