The current study used a single-case design to examine two performance feedback conditions varying in intensity on the frequency of naturalistic math instruction in preschool classrooms during non-instructional times (transition, lunch, free play). Three Head Start teachers received professional development that combined information on four math-oriented milieu teaching strategies (incidental teaching, time delay, mand model, and model), milieu teaching scripts, and goal setting. Teachers then received a feedback package of relatively higher intensity associated with a performance criterion followed by lower-intensity, continued support feedback package. Teachers increased the use of math-oriented milieu teaching strategies and positive attention across intervention conditions. In addition, two of the three teachers evidenced generalization of milieu teaching strategies across contexts and content areas. Results are discussed in terms of conceptualizations of intervention intensity and implications for practice, limitations, and future directions.