The purpose of this study was to identify important sociodemographic factors affecting the utilization of immediate and early delayed postmastectomy breast reconstruction in the United States. Using the Surveillance, Epidemiology, and End Results (SEER) program, all cases of mastectomy-treated breast cancer that were reported to a SEER registry in 1998 were identified. Data were limited to reconstructions within the first 4 months postmastectomy, and logistic regression was used to analyze the effects of sociodemographic variables on reconstruction rates. Of the 10,406 mastectomy-treated breast cancer patients, 1607 (15 percent) underwent reconstruction within the first 4 months postmastectomy. Compared with women 45 to 54 years old, those 35 to 44 years old were significantly more likely to have breast reconstruction (OR = 1.52, p < 0.001), but women 55 to 64, 65 to 74, and 75 years and older were significantly less likely to have reconstruction (OR = 0.42, p < 0.001; OR = 0.16, p < 0.001; OR = 0.04, p < 0.001, respectively). Compared with Caucasian women, African American, Hispanic, and Asian women were significantly less likely to have reconstruction (OR = 0.48, p < 0.001; OR = 0.45, p < 0.001; OR = 0.29, p < 0.001, respectively). In addition, a four-fold difference in reconstruction rates existed in high-use versus low-use regions. With regard to the type of reconstruction, patients younger than 35 and 65 to 74 years old were significantly less likely to receive autogenous tissue reconstruction compared with women 45 to 54 years old (OR = 0.47, p = 0.047; OR p = 0.61, p = 0.031, respectively). However, African Americans were significantly more likely to receive autogenous tissue reconstructions compared with Caucasians (OR = 2.03, p = 0.021). According to these data, the utilization of immediate and early delayed breast reconstruction in the United States is low and is significantly influenced by patients' age, race, and geographic location. Further research is needed to evaluate the impact of provider bias, patient preference, and barriers to care on the utilization of breast reconstruction in the United States.