OBJECTIVES:  A twice weekly maintenance treatment strategy with tacrolimus ointment for atopic dermatitis significantly delayed and reduced the number of disease flares over a 12-month period compared with the standard reactive tacrolimus treatment strategy. The aim of this post hoc analysis was to evaluate the cost-effectiveness of the maintenance strategy versus the reactive strategy in adults and children with moderate and severe atopic dermatitis (AD). METHODS: The evaluation was performed using a decision analytic model based on the results of two pivotal phase III trials that were conducted in adults and children receiving 0.1% and 0.03% tacrolimus ointment, respectively. Clinical data were taken from the clinical trials and utility data were derived from a published source. The time horizon was 12 months; costs and utilities were applied to the treatment period and to any remaining days in the 12-month period post-tacrolimus discontinuation. Sensitivity analyses assessed the degree of uncertainty around the results. The analysis was conducted from the perspective of the UK National Health Service. RESULTS: In the base-case analysis for both adults and children with moderate and severe AD, the maintenance treatment strategy with tacrolimus ointment was dominant over the reactive treatment strategy in that it was more effective and less costly. In univariate sensitivity analyses, for all patient groups, few parameters when varied between the value of their upper and lower confidence interval resulted in incremental cost-effectiveness ratios (ICERs) above zero. Probabilistic sensitivity analyses demonstrated that the probability of tacrolimus maintenance treatment being dominant over the reactive treatment strategy was; 76% for adults with moderate AD, 89% for adults with severe AD, 75% for children with moderate AD and 54% for children with severe AD. CONCLUSIONS: Maintenance use of tacrolimus ointment is a dominant treatment strategy compared with reactive use, providing incremental health benefits at a lower cost.