The Massachusetts healthcare environment has been moving steadily over recent years from a collection of individual hospitals to a collection of large hospital systems with members bound together through either mergers or creative affiliations.

On Monday,  Anna Jaques Hospital  of Newburyport announced that it had signed a letter of intent to explore a merger with  Beth Israel Deaconess Medical Center, Lahey Health,  and  New England Baptist Hospital (NEBH) . And days later, on Thursday,  Mount Auburn Hospital  of Cambridge announced the same thing – an exploration of a merger with the BIDMC-Lahey-NEBH entity.

NEBH had announced its merger intentions in April and BIDMC and Lahey announced the merger of their existing systems in January 2017. All of the entities are either in negotiations or have announced that negotiations will begin. But none of the entities to date have filed the necessary papers with the Health Policy Commission, which reviews all mergers and affiliations.