While forecasters a decade ago warned of large shortages of registered nurses, the nursing workforce has in fact grown to 2.7 million in 2012 -- 500,000 more than previously projected. Now, a new study shows that a significant portion of the increase is due to many baby boomer nurses retiring at a later age -- a trend that predates the recent recession. Using Census Bureau and other nationally representative survey data, the authors found that, from 1969-90, 47% of RNs working at age 50 were still working at age 62 and 9% were working at age 69. In contrast, in the period 1991-2012, the rates were 74% at age 62 and 24% at age 69. This trend extended nursing careers by 2.5 years after age 50 and expanded the 2012 RN workforce by 136,000, according to findings in Health Affairs. Since many RNs transition away from hospital settings as they age, the increase in RNs' career longevity may imply a boost for RN employment in nonhospital settings such as nursing homes, home health care and ambulatory care centers. Read the abstract.