In accordance with a Massachusetts school nutrition bill (105 CMR 225.000) passed in 2010, the Massachusetts Departments of Public Health and Elementary and Secondary Education have developed new nutrition standards for all competitive foods and beverages served in schools in the state. These standards will be the most comprehensive in the U.S. and most closely reflect all aspects of the Institute of Medicine’s competitive food recommendations. This natural experiment will evaluate the new competitive food policy in Massachusetts, with Rhode Island serving as a control state. The specific aims of the study are to: 1) assess schools’ compliance with new state nutrition standards in Massachusetts and the barriers to prompt compliance; 2) evaluate the financial impact of healthier nutrition standards on food and beverage sales for both competitive foods and school meals in Massachusetts compared with finances in Rhode Island where competitive foods are unchanged; 3) determine which strategies lead to the most successful implementation of the new standards and those that best prevent revenue losses in Massachusetts as well as strategies for serving healthier foods and beverages in Rhode Island; 4) assess if the legislation leads to product reformulation and/or increased availability of healthier competitive foods/beverages in schools in Massachusetts; and 5) examine students’ consumption of foods and beverages both during and outside of the school day in Massachusetts compared with Rhode Island. This study will inform the development of best practice approaches for other states and federal regulators as they consider implementing similar policies in the future.