School Modernization and Efficient Access to Lunches for Students Act of 2023 or the School MEALS Act of 2023 This bill establishes programs and revises requirements relating to direct certification processes for the National School Lunch Program. Direct certification allows schools to use data matching procedures to approve school meals without the need for applications for children who receive assistance under other programs, such as the Supplemental Nutrition Assistance Program (SNAP). Specifically, the bill directs the Department of Agriculture to provide grants and technical assistance for states and tribal organizations to improve their direct certification processes, including with respect to children who receive assistance under a food distribution program on Indian reservations. The bill also expands the time frame for schools to elect and gather eligibility data for the Community Eligibility Provision that permits schools in high-poverty areas to serve free meals to all enrolled students without the need for applications. Further, the bill specifies that a state subject to a continuous improvement plan (for not directly certifying at least 95% of children eligible for direct certification because they receive SNAP benefits) must implement the improvement measures within three years.