MBTA Board Chair Thomas Glynn will step down and be replaced by a long-time board member and former mayor of Lynn, Gov. Maura Healey announced Monday.

A veteran MBTA leader will soon end his tenure chairing the agency's board, and a former co-chair of the Legislature's Transportation Committee will step into the role at a pivotal point.

MBTA Board of Directors Chair Thomas Glynn plans to step down on Nov. 1. Gov. Maura Healey picked Thomas McGee, who also spent four years as mayor of Lynn, to succeed him.

A veteran MBTA leader will soon end his tenure chairing the agency’s board, and a former co-chair of the Massachusetts Legislature’s Transportation Committee will step into the role at a pivotal point.

Replacement Thomas McGee, a 23-year veteran of the Legislature, will lead the board during a stretch when the agency's standing on Beacon Hill will be critical.