Ankylosing spondylitis (AS) is the most frequent prototype of spondyloarthritides. Substantial direct costs and productivity losses often arise in young patients. Currently, tumor necrosis factor (TNF) inhibitors are the only approved therapy escalation when usual care (physiotherapy and NSAIDs) proves to be insufficient. Owing to their high medication costs, TNF inhibitors are a target of cost-effectiveness analyses. There is consistent evidence regarding the use of TNF inhibitors according to recommendations in patients with active AS finding TNF inhibitors to be cost effective from a societal perspective. However, there are relevant uncertainties (discontinuation rate and progression rate) in the long-term estimates of the cost-effectiveness analyses analyzed. Whether TNF inhibitors are cost effective from an insurance perspective in the long run will have to be addressed by models based on observational data.