This study examined national trends and projections of procedure volumes and prevalence rates for shoulder and elbow arthroplasty in the United States (U.S.). This study hypothesized that the growth in demand for upper extremity arthroplasty will be greater than the growth in demand for hip and knee arthroplasty and that demand for these procedures will continue to grow in the immediate future. The Nationwide Inpatient Sample (1993-2007) was used with U.S. Census data to quantify primary arthroplasty rates as a function of age, race, census region, and gender. Poisson regression was used to evaluate procedure rates and determine year-to-year trends in primary and revision arthroplasty. Projections were derived based on historical procedure rates combined with population projections from 2008 to 2015. Procedure volumes and rates increased at annual rates of 6% to 13% from 1993 to 2007. Compared with 2007 levels, projected procedures were predicted to further increase by between 192% and 322% by 2015. The revision burden increased from approximately 4.5% to 7%. During the period studied, the hospital length of stay decreased by approximately 2 days for total and hemishoulder procedures. Charges, in 2007 Consumer Price Index-adjusted dollars, increased for all 4 procedural types at annual rates of $900 to $1700. The growth rates of upper extremity arthroplasty were comparable to or higher than rates for total hip and knee procedures. Of particular concern was the increased revision burden. The rising number of arthroplasty procedures combined with increased charges has the potential to place a financial strain on the health care system. Copyright © 2010 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.