The US hospice industry, which provides palliative and supportive care to patients with terminal illness, has undergone substantial changes during the last decade. The magnitude of these changes has not been fully captured in previous studies or reports. In this longitudinal study of hospices active in Medicare during 1999–2009, we analyzed Provider of Services files to understand key shifts in the industry. We found evidence of substantial turbulence. One-fifth of Medicare-certified hospices active in 1999 had closed or withdrawn from the program by 2009, and more than 40 percent had experienced one or more changes in ownership. The most prominent trend was the shift in ownership type from nonprofit to for-profit ownership. Four out of five Medicare-certified hospices that entered the marketplace between 2000 and 2009 were for-profit. Hospices also became larger, as the proportion with 100 or more full-time employees doubled to 5 percent from 1999 to 2009. Although each of the Census regions had more hospices in 2009 than in 1999, the geographic distribution of hospices in the country changed, with proportionally more in the South and West. The impact of all of these changes on cost and quality of hospice care, as well as patient access, remains a critical area for future research.