Background: Use of the intrauterine device (IUD) in the United States has recently increased. New evidence for women with employer-sponsored health insurance permits analysis of variation and trends in such use. Study Design: A retrospective analysis of annual IUD insertion rates between 2002 and 2008 was conducted by evaluating claims from the MarketScan® Commercial Research Databases for US women insured by plans that covered IUD insertions. Estimates were weighted to be nationally representative. Results: IUD insertion rates increased from 1.6/1000 women of reproductive age to 9.8/1000 over 2002-2008 and varied substantially by state. Insertion rates of the levonorgestrel-releasing intrauterine system (LNG-IUS) increased from 0.4/1000 to 7.7/1000, whereas the insertion rates of copper T380A IUD (copper IUD) increased from 0.6/1000 to 1.5/1000. IUD insertions, which are most common among women aged 25-34 years, increased at roughly the same rate across all age groups. Conclusions: The sixfold increase in IUD insertion rates between 2002 and 2008 was accompanied by an increase in the share IUD use with the LNG-IUS from 40% to 85%. Substantial geographic and age variations existed. © 2012 Elsevier Inc. All rights reserved.