OBJECTIVES: To provide an overview of trends in prices of biological disease-modifying anti-rheumatic drugs (biologic DMARDs) approved by the US Food and Drug Administration (FDA) in the period 1997-July 2015, and to evaluate trends in biological DMARD prices before and after the introduction of the Medicare Part D (2006) and Affordable Care Act (2010). METHODS:  Regulatory information for biologicals was obtained from the FDA. Average wholesaler prices (AWP) per unit at market entry was obtained from the RedBook (Truven Health Analytics). The defined daily dose (DDD) for adult patients was obtained from the World Health Organization. Prices were converted to 2015 dollars using the consumer price index. Descriptive statistics, Mann Whitney-Wilcoxon rank and Kruskal-Wallis tests were performed. Statistical significance level was set at 0.05.  RESULTS: FDA approved 10 biological DMARDs: 5 anti-tumor necrosis factor (anti-TNF) and 5 non anti-tumor necrosis factor (non anti-TNF) drugs. There was a significant increase in the median AWP per DDD overtime, the median AWP per DDD was $39.61 in the 1990s, $76.23 in the 2000s, and $102.92 in the period 2010–July 2015. The AWP annual compound growth rate ranged from 2.5% for infliximab to 11% for certolizumab. The total percentage increase of AWP in the study period ranged from 13.8% for tocilizumab to 249.4% for etanercept. Biological DMARDs administered subcutaneously had a significantly higher AWP per DDD ($112.79) as compared to biologicals administered intravenously ($79.16) (p= 0.03). The median AWP per DDD significantly increased after the introduction of Medicare Part D (2006) and the Affordable Care Act (2010). CONCLUSIONS: Biological DMARD prices increased substantially over time. Biological DMARDs administered subcutaneously had higher prices than biological DMARDs administered intravenously. Prices for biological DMARDs significantly increased after the introduction of Medicare Part D (2006) and the Affordable Care Act (2010).