The bill amends Chapter 33 of the General Laws to enhance the governor's authority regarding the operation of out-of-state military units that have not been federalized. It establishes that such military units must obtain prior written authorization from the governor to operate within Massachusetts, along with acknowledgment of the governor's control and conditions for their operations. Additionally, the governor is required to notify members of the House of Representatives and the Senate about the conditions of any authorized military operations, including their scope, purpose, and duration. The bill also stipulates that military units operating without this authorization will be subject to the state's civil and criminal laws.

Furthermore, the bill mandates that the governor must notify the legislature within a specified timeframe upon receiving credible information about any mobilization affecting military units within or from the Commonwealth. This notification must include details such as the scope, purpose, and anticipated duration of the mobilization, as well as any limitations on the reliability of the information. The governor is also required to provide supplemental notifications if any initial information is found to be inaccurate or if new information arises. The obligation for these notifications will cease once all affected military units are fully withdrawn or demobilized, or after 90 days from the initial notification, unless extended by the legislature.