Variability in Dietary Quality of Elementary School Lunch Menus with Changes in National School Lunch Program Nutrition Standards

National School Lunch Program (NSLP) standards recently changed significantly. The Healthy, Hunger-Free Kids Act (HHFKA) presumably improved the dietary quality (DQ) of meals, whereas Child Nutrition Program (CNP) Flexibilities appear to decrease DQ. This variability has not been quantified. Our objective was to determine differences in DQ between elementary school lunch menus meeting NSLP standards: School Meal Initiative (SMI), HHFKA, CNP Flexibilities, and evidence-based best practices (BP). A base menu was portioned per NSLP standards and analyzed for nutrient content and DQ. Statistical analyses included 1-factor ANOVA, Kruskal–Wallis, and Dunnett's test. The BP menu had higher whole fruit and whole grain Healthy Eating Index scores than SMI (Ps < 0.0083). The BP and HHFKA menus had higher refined grain and added sugars scores than SMI (Ps < 0.0083). The SMI menu had lower total vegetable and saturated fat scores than all menus (Ps < 0.0083). This study informs policy toward improving standards, positively affecting child health and academic performance through higher-DQ lunches.