A: The four cities that gained the most retirees who relocated across state lines between 2005-2010 were Phoenix, Tampa, Atlanta, and Las Vegas. When considering relocating for retirement, it is important to consider factors such as housing and other costs of living, taxes, crime rates, weather and air quality, doctor availability, and opportunities for an active lifestyle, including walking, bicycling, and volunteering. To read more about the best places to retire, see: Retirement Relocation – Key Insights.