In response to economic distress and food insecurity during the COVID-19 pandemic, Congress expanded the Supplemental Nutrition Assistance Program (SNAP) by introducing emergency allotments to increase monthly benefits, starting in March 2020. In March 2023, emergency allotments expired in the thirty-five states and territories still offering them. We provide some of the first evidence of the impacts of this loss of nutrition support-in some cases, more than $250 a month-for economically disadvantaged households. Our quasi-experimental study examined the effects of the program's expiration on food insufficiency, mental health, and financial well-being, using data from the Census Bureau's Household Pulse Survey. In difference-in-differences analyses, we compared pre-post differences among SNAP participants with pre-post differences among income-eligible nonparticipants. The emergency allotment expiration led to a substantial increase in food insufficiency (8.4 percentage points) and greater food pantry use (2.1 percentage points) and difficulty paying expenses (2.0 percentage points). Non-Hispanic Black SNAP participants experienced a greater increase in anxiety symptoms compared with non-Hispanic White SNAP participants. This study has implications for ongoing policy making with respect to nutrition and safety-net programs to support vulnerable families, especially amid inflated food prices.