OBJECTIVES:  Overuse of antibiotics in children is a growing concern in the US. One of the important HEDIS quality measures used to compare performance of health plans incorporates appropriate prescribing of antibiotics for children with pharyngitis. The current study examined this measure over four years to determine if physician behavior had changed over time. METHODS:  Patients aged 2-18 diagnosed with pharyngitis (ICD-9-CM 462, 463 and 034.0) on a medical claim (‘index’) and dispensed an antibiotic were identified in administrative claims data from the Truven Health MarketScan® Research databases (2008-2012). From this eligible population, the proportion of patients having evidence of a streptococcus test in the seven-day period from three days prior to index through three days post-index was calculated. A higher rate represents better performance (i.e., appropriate testing). Rates were examined overall and by age group. RESULTS: In fiscal year (FY) 2009, 68.9% of eligible patients had evidence of a streptococcus test. Appropriate testing rates were highest for patients aged 5-7 and 8-10 (76.1% and 75.1%, respectively) and lowest for those aged 14-16 and 17-18 (62.0% and 59.9%, respectively). The rate of appropriate testing grew slightly in FY2010 to 70.2% with very similar age-group specific rates. In FY2011, the overall rate grew by nearly 6% to 74.3%. Age group trends continued, with 80.3% of patients aged 5-7 and 78.3% of patients aged 8-10 appropriately tested. In FY2012 the overall rate grew to 76.0%, with patients aged 5-7 and 8-10 continuing to have the highest rate of testing (81.1% and 80.8%, respectively) and those aged 14-16 and 17-18 the lowest rate (71.6% and 67.0%, respectively). CONCLUSIONS: The rate of appropriate testing for antibiotic use in children with pharyngitis increased by 10% between FY2009 and FY2012. While the trend is moving in the right direction, significant room for improvement remains.