Background: As part of recertification, the American Board of Internal Medicine requires its diplomats to complete at least 1 practice improvement module (PIM). We assessed whether completing an asthma-specific PIM resulted in improved patient outcomes. Methods: Practices were the unit of randomization in this cluster randomized trial. Physicians in the intervention group were asked to complete the PIM through its planning phase. The primary outcome was the dispensing of an inhaled corticosteroid (ICS) after a postintervention visit for asthma. Secondary outcomes included patient reported processes of care, asthma-related heath care use, and asthma severity. Analyses were adjusted for baseline rates at the cluster-level as well as for individual sociodemographic characteristics. Results: Eight practices (19 internists) were randomized to the intervention group and 8 practices (21 internists) to the control group. For the primary outcome, ICS fill rates, patients seen by intervention group physicians were not more likely to fill an ICS prescription in the post-intervention period than patients seen by control group physicians (adjusted odd ratio [AOR], 1.00; 95% confidence interval [CI], 0.64-1.56). Patients seen for asthma by intervention group physicians were less likely to receive a written action plan than patients seen by control group physicians (AOR, 0.67; 95% CI, 0.48-0.93); however, they were more likely to discuss potential asthma triggers (AOR, 1.62; 95% CI, 1.08-2.42) and had lower self-reported asthma severity measures (unadjusted P=.03). Per-protocol analysis supported the latter 2 associations. Conclusion: A PIM designed to improve asthma care did not improve filling of ICS prescriptions but may have lessened asthma severity through an increased discussion of asthma triggers.