Houghton Mifflin Harcourt will be moving its Boston headquarters to new offices in early 2017.

The company has signed a 16-year lease to take over the entire fifth through eighth floors in the High Street Tower, giving it 162,000 square feet of space. HMH’s current offices are in Boston’s Back Bay section.

HMH’s soon-to-be new home, 125 High Street, is a three-building, 1.5-million square-foot development located within Boston’s Financial District. The complex includes three buildings and recently achieved LEED Gold for Existing Buildings certification under the U.S. Green Building Council’s LEED rating system.