Kindred Healthcare is planning a $39.5 million expansion of its headquarters along Fourth Street at Broadway, adding up to 500 additional employees over perhaps three years. The health care giant will build a six-story, 142,000-square-foot building adjacent to the current corporate headquarters facing The Brown hotel that will house a support center for training, an employee wellness clinic and other operations. Kindred said ground may be broken next summer, with construction to take around two years. Kindred officials were joined by Gov. Steve Beshear and Mayor Greg Fischer Thursday afternoon at Theater Square to announce the new jobs and the construction, after the state Economic Development Finance Authority reviewed a set of $11 million in state incentives for the expansion earlier in Frankfort.