In 2019, California and Wilmington, Delaware implemented policies requiring healthier default beverages with restaurant kids’ meals. The current study assessed restaurant beverage offerings and manager perceptions in a sample of quick-service restaurants. Pre-implementation, the most common kids’ meal beverages on California menus were unflavored milk and water (78·8 %, 52·0 %); in Wilmington, juice, milk and sugar-sweetened beverages were most common (81·8 %, 66·7 % and 46·2 %). Post-implementation, menus including only policy-consistent beverages significantly increased in California (9·7 % to 66·1 %, P < 0·0001), but remained constant in Wilmington (30·8 %). During orders, cashiers/servers offering only policy-consistent beverages significantly decreased post-implementation in California (5·0 % to 1·0 %, P = 0·002). Few managers (California 29·3 %; Wilmington 0 %) reported policy knowledge, although most expressed support. Most managers wanted additional information for customers and staff. While the proportion of menus offering only policy-consistent kids’ meal default beverages increased in California, offerings did not change in Wilmington. In both jurisdictions, managers lacked policy knowledge, and few cashiers/servers offered only policy-consistent beverages. Additional efforts are needed to strengthen implementation of kids’ meal beverage policies.