In June, Maine passed a law allowing patients from other locations with medical marijuana programs to use their authorized medical marijuana cards at Maine dispensaries, so long as the jurisdiction opts in.

Twenty-five states and the District of Columbia signed on to the Maine initiative earlier this summer — including Connecticut, New Hampshire, Rhode Island, and Vermont — and on Tuesday, Massachusetts was added to the most recent list published by Maine officials.

“We were pleased to work with the Massachusetts Cannabis Control Commission to add the Commonwealth to our list of authorized states,” David Heidrich Jr., the director of engagement and community outreach in Maine’s Office of Marijuana Policy, wrote in an e-mail. “Such a step is important, given our regional proximity, to the medical marijuana patients from Massachusetts that visit our remarkable state for both work and vacation.”