Starting with the 2008 SAHIE estimates, the SAHIE program updated its methodology to incorporate the estimates of health insurance coverage from the American Community Survey (ACS). The incorporation of the ACS into the modeling procedures has allowed for more detailed income group data as well as a higher level of precision in the estimates.

"Data Inputs" describes the data that are used in the models to produce SAHIE estimates. It discusses the sources of each dataset, key concepts, and any adjustments made to the data.

Due to these methodological differences, comparisons between ACS-based SAHIE estimates and earlier years are not recommended. Guidance on comparisons within the ACS-based estimates is available.