In the setting of changing temporal trends in the management of osteoporosis, we examined how select characteristics of new oral bisphosphonate (BP) initiators changed over time among 94,073 women within a large, integrated healthcare organization during the period 2004 to 2012. In the earlier era (2004-2007), approximately half of women younger than 65 years initiating BP therapy (47%-54%) had osteoporosis by bone mineral density (BMD) criteria, but this proportion increased sharply in the later era (2008-2012), with 55% to 81% having osteoporosis. This trend was not evident in older women (≥65 years). The proportion of younger women with prior fracture increased from 15% in 2008 to 32% in 2012, after remaining relatively stable (10%-15%) during the earlier era. Again, this trend was not observed among older women. Thus, among women younger than 65 years, we observed a marked temporal shift in initiation of BP treatment toward women at high risk (including those with prior fracture and those with osteoporosis by BMD testing) and away from those at lower risk (such as those with osteopenia and/or no prior fracture).