In this paper, we link state Supplemental Nutrition Assistance Program (SNAP) administrative records to the Current Population Survey Annual Social and Economic Supplement (CPS ASEC) to examine two main outcomes related to poverty measurement. The first is the accuracy with which self-reported SNAP participation and associated amounts in the CPS ASEC align with administrative records. The second is the extent to which, when values do not align, replacing values with administrative records affects the Supplemental Poverty Measure (SPM) rate. Analyzing data for Illinois, Maryland, Oregon, and Virginia, we find that using administrative records matters for measuring poverty. Pooling the four states in our analysis, the SPM rate decreases by 0.6 percentage points when SNAP administrative records are used instead of survey self-report. This is mostly driven by the fact that in these four states, at least 40 percent of SNAP recipients do not report any SNAP receipt in the CPS.