The Martha’s Vineyard Hospital this week came a step closer to realizing a three-year plan to reshuffle the Island’s mental health and walk-in clinic services, and gain extra parking space at the same time.

The plan involves a three-way deal, in which land adjacent to the hospital, now owned by the state Department of Mental Health (DMH) will be handed over to the hospital to be used as a parking lot.

In return, the hospital intends to provide the DMH with alternative premises, understood to be the Vineyard Medical Services walk-in clinic on State Road in Vineyard Haven.

The only glitch is that the hospital does not own the clinic. It is owned by Dr, Michael Jacobs, a well-known internist and primary care doctor to many Islanders.

Nonetheless, the real estate round-robin was presented as a done deal in a press release on Wednesday from Cape and Islands Rep. Tim Madden, announcing that Senate Bill 2146, An Act Relative to Martha’s Vineyard Hospital, sponsored by himself and Cape and Islands Sen. Robert O’Leary, “has been enacted in law.”

The release also said: “This bill authorizes the transfer of a lot of land adjacent to Martha’s Vineyard Hospital owned by the Department of Mental Health (DMH) to MVH in return for a lot of land with a building that is suitable for DMH services.”

That unnamed building, the release said, “currently houses a clinic that would be a suitable host for DMH services.”

It continued, quoting Mr. Madden: “I’m pleased we were able to pass it before the holidays. This land swap is a win for both the Martha’s Vineyard Hospital as well as the Department of Mental Health, which will allow both organizations to provide these vital services for Vineyarders.”

Later Nell Coogan, the legislative liaison to the Vineyard for Mr. Madden, identified the premises as the walk-in clinic, and conceded that the details of the deal were vague.

“As far as we know, no one was against this whole thing happening,” she said.

“At first I was concerned about the clinic, but they seem to want this too. But that’s about as much as I know. We were asked to push the bill, but we weren’t in on the specifics of the deal.”

Ms. Coogan suggested talking to Senator O’Leary’s office for further details. But they also were unable to provide any.

It is known that the hospital, which is nearing completion on a $50 million new facility at its campus in Oak Bluffs, needs the extra parking lot as a condition of its approval by the Martha’s Vineyard Commission for the building.

The walk-in clinic is one of only two such clinics on the Vineyard — the other being in Edgartown. Yesterday, no one was available to talk about the deal and in particular about what would happen to the heavily-patronized practice at the walk-in clinic.

The hospital did not return telephone calls from the Gazette, and Dr. Jacobs declined to comment.

But it is understood negotiations between the hospital and Dr. Jacobs have been ongoing for some three years, and have yet to be concluded.

If and when the hospital does buy Dr. Jacobs’s building, walk-in medical services are expected to move to the hospital, furthering the vertical integration of the Island’s health services under the hospital and its parent, Massachusetts General Hospital and Partners Healthcare.

Whether Dr. Jacobs and his staff will also move to the hospital is unknown.