Mass. Gen. Laws ch. 25 § 5E
The department may, from time to time, audit all companies subject to its jurisdiction, except steam distribution companies. Such audits may include, but shall not be limited to, review of the following documents: (a) all financial statements, the balance sheet, the income statement, the statement of cash flows, the statement of retained earnings, the notes to the financial statements, and the information in the annual return to the department; (b) all documents concerning reconciling mechanisms related to rates, prices, charges, or costs and savings related to a merger, acquisition or consolidation within 3 years after the merger, acquisition or consolidation; and (c) documents concerning service quality measure statistics and service quality performance at least every 3 years or whenever service quality penalties equal to or exceed 50 per cent of the maximum.
Upon written complaint of the attorney general requesting an independent audit of a company subject to the departments jurisdiction, the department shall commence a proceeding within 30 days of receipt of the complaint for the purpose of ordering the requested audit in a reasonable time. The results of any audit so ordered shall be filed promptly with the department and each audit shall be paid for by the company that is the subject of the audit.
Mass. Gen. Laws ch. 25, § 5E