Boston’s Green Line extension to Somerville and Medford likely will be delayed again due to rising costs, Massachusetts Dept. of Transportation officials said on Oct. 21. Preliminary analysis indicates project costs may exceed the latest budget estimates by as much as $1 billion, Massachusetts Bay Transit Authority General Manager Frank DePaola said in a statement.

In January, the Federal Transit Administration agreed to contribute $996 million, which will provide half the almost $2 million in the then-current project capital cost. MassDOT will deliver a report on the extension project to Gov. Charlie Baker (R) and the fivemember MassDOT Fiscal Management and Control Board by the Dec. 9 joint board meeting. MassDOT has hired law firms Nossaman and Foley Hoag to provide project-delivery analysis; the Berkeley Research Group to perform look-back analysis; and the Arup Group for costreduction design review.