Healthy aging has emerged as one of the major public health opportunities of the 21st century. Since the turn of the last century, there have been dramatic improvements in life expectancy. From1900 through 1902, life expectancy at age 65 was 12 years; by 2005, life expectancy for this age group had increased to 18.7 years (1,2). The proportion of the U.S. population aged 65 and over more than tripled from 1900 (4.1%) through 2000 (12.4%) (3). According to U.S. Census Bureau projections, by 2030 adults aged 65 and over are expected to constitute 20% of the total U.S. population (4). The age group examined in this report—adults aged 55 and over—is expected to constitute nearly one-third (31.1%) of the population by 2030.