OBJECTIVES: Little is known on how pulmonary arterial hypertension (PAH) may impact worker productivity. The objective of this study was to estimate indirect costs of PAH in an employed population. METHODS: Data came from Truven’s MarketScan Health and Productivity Management database. PAH workers were identified based on having >2 medical claims for primary pulmonary hypertension (ICD-9 code:416.0), and either one claim for right heart catheterization or one claim of echocardiogram. The first medical claim during this period served as in the index date with 6 months prior to this event as baseline and 12 months post as follow-up period.  Three non-PAH employees were matched to each PAH worker on age, gender, census region, and plan type.  Annual productivity loss was calculated as a sum of absenteeism and short term disability (STD) in the follow-up year and derived by multiplying the reported days off work times the industry-specific average daily wage rate obtained from the 2012 US Department of Labor.  RESULTS: