Scaling up effective policies often requires the attention of frontline bureaucrats with many competing responsibilities. Even when policymakers adopt effective programs, implementation may not follow. In a nationwide experiment in the Dominican Republic, we test interventions to increase school principals' implementation of an educational program proven effective in a previous RCT. Only 37% of control schools verifiably implemented the intervention when ordered to by the Ministry of Education, compared with 83% in the original trial. Implementation was no higher among schools that previously implemented the program in the RCT, suggesting that fixed costs of adoption do not explain non-adoption. We find precise null effects of sharing research evidence, providing modest financial incentives, or offering implementation assistance to principals. In contrast, additional reminder calls increased implementation by 20 percentage points. A second experiment targeting a different mandated program yields the same pattern: reminders produce large effects, while monitoring messages have smaller effects. Our findings point to limited attention among bureaucrats as an important barrier to scaling policies.