BACKGROUND: The 2013-2014 school year involved preparation for implementing the new US Department of Agriculture (USDA) competitive foods nutrition standards. An awareness of associations between commercial supplier involvement, food vending practices, and food vending item availability may assist schools in preparing for the new standards. METHODS: Analyses used 2007-2012 questionnaire data from administrators of 814 middle and 801 high schools in the nationally representative Youth, Education, and Society study to examine prevalence of profit from and commercial involvement with vending machine food sales, and associations between such measures and food availability. RESULTS: Profits for the school district were associated with decreased low-nutrient, energy-dense (LNED) food availability and increased fruit/vegetable availability. Profits for the school and use of company suppliers were associated with increased LNED availability; company suppliers also were associated with decreased fruit/vegetable availability. Supplier “say” in vending food selection was associated with increased LNED availability and decreased fruit/vegetable availability. CONCLUSIONS: Results support (1) increased district involvement with school vending policies and practices, and (2) limited supplier “say” as to what items are made available in student-accessed vending machines. Schools and districts should pay close attention to which food items replace vending machine LNED foods following implementation of the new nutrition standards.