OBJECTIVES: We assessed above-label dosing and associated costs for etanercept (ETA), adalimumab (ADA), certolizumab (CER), golimumab (GOL), and ustekinumab (UST) among moderate to severe psoriatic arthritis (PsA) patients.  METHODS: We identified adult PsA patients enrolled in the MarketScan claims database between 01/01/2011-12/31/2013. Patients had ≥1 PsA diagnosis, ≥1 pharmacy claim for ETA, ADA, CER, GOL, or UST, and were followed up for 12 months with an additional 3-month look-forward period to qualify as continuously treated. Patients were excluded if they had any other autoimmune disease indicated for treatment with biologics of interest. Clinically meaningful above-label use was defined as a maintenance dose ≥10% higher than indicated in the label for >6 months during the follow-up period. Percent of patients with above-label use, mean days of above-label use, and additional costs associated with above-label use (above-label minus on-label cost) were examined. RESULTS: This study identified 4,245 PsA patients on ETA (n=2,342), ADA (n=1,788), and GOL (n=115).  Patients on CER (n=0) or UST (n=14) were not included due to small sample size, presumably as a result of more recent approval for PsA. Above-label use occurred in 9.6% of ADA patients (mean [SD] above-label use of 292 [55] days), 4.1% of ETA patients (279 [57] days), and 2.6% of GOL patients (341 [29] days). These findings translate into excess daily costs per patient of $67 for ADA, $77 for ETA, and $44 for GOL; the corresponding excess annual costs for each patient (mean values adjusted to 2014) were $19,564, $21,483, and $15,004, respectively.  Overall incremental costs among all patients with above-label use were $3,345,444 for ADA, $2,040,885 for ETA, and $45,012 for GOL. CONCLUSIONS: PsA patients treated with ETA, ADA, and GOL have above-label use, translating to excess cost of biologics to payers when compared with on-label use. Sponsored by Novartis Pharmaceuticals Corporation.