To help support activities of the National Johnes Working Group in the control of Johnes disease on U.S. dairy operations, one of the objectives of the National Animal Health Monitoring System (NAHMS) Dairy 96 Study, conducted by the U.S. Department of Agriculture: Animal and Plant Health Inspection Service: Veterinary Services, was to evaluate associations between specific herd management practices and Mycobacterium paratuberculosis herd infection status. Previous results from this study with over 1000 participant operations in 20 states showed at least 20% of U.S. dairy operations were infected with M. paratuberculosis and estimated the economic loss to heavily infected herds at over $200 US per cow (infected and noninfected) per year. From multivariable analysis accounting for the study design, factors associated with herd M. paratuberculosis status included herd size, region, percent of milk cows born off the operation, use of multiple cow maternity housing, and use of multiple calf preweaned calf housing. Of particular value to Johnes disease educational efforts was the finding that familiarity or previous diagnosis with Johnes disease were not associated with use of preventive management practices.