Despite its benefits in body image, self-esteem, sexuality, and quality of life, historically fewer than 25 percent of patients undergo immediate breast reconstruction. After passage of the Women Health and Cancer Rights Act, studies failed to demonstrate changes in reconstructive rates. A recent single-year report suggests significant shifts in U.S. breast reconstruction patterns. The authors' goal was to assess long-term trends in rates and types of immediate reconstruction. A serial cross-sectional study of immediate breast reconstruction trends was performed using the Nationwide Inpatient Sample database from 1998 to 2008. Data on mastectomies, reconstructive method (autologous/implant), and sociodemographic/hospital predictors were obtained. Immediate breast reconstruction rates increased on average 5 percent per year, from 20.8 percent to 37.8 percent (p < 0.01). Autologous reconstruction rates were unchanged. Implant use increased by an average of 11 percent per year (p < 0.01), surpassing autologous methods as the leading reconstructive modality after 2002. The strongest predictors of implant use were procedures performed after 2002, bilateral mastectomies, patients operated on in Midwest/West regions, and Medicare recipients. In contrast to bilateral mastectomies, which increased by 17 percent per year (p < 0.01), unilateral mastectomies decreased by 2 percent per year (p < 0.01). Bilateral mastectomy defects had significantly higher reconstruction rates than unilateral counterparts (p < 0.01). The significant rise in immediate reconstruction rates in the United States correlates closely to a 203 percent expansion in implant use. Although the reason for the increase in implant use is multifactorial, changes in mastectomy patterns, such as increased use of bilateral mastectomies, are one important contributor.