The Office of the Comptroller is an independent agency within the Executive Branch. The Comptroller’s role is to work with Commonwealth fiscal officers in over 150 Departments to ensure the integrity, accountability and efficiency of the Commonwealth's fiscal operations, communicate accurate and timely financial information to decision makers within the Executive, Legislative and Judicial Branches, the financial community as well as the general public, and provide leadership and professional guidance in areas of fiscal policy within the Commonwealth and nationally. The Office is committed to accomplishing this mission in partnership with all Commonwealth fiscal officers.

The Office of the Comptroller's day-to-day activities, as well as long term initiatives, are closely coordinated with other Central Service Agencies, cabinet secretariats and constitutional offices. These activities include: payables management (vendor registration, contract management, payments and tax reporting); receivable management (automated billing and settlement, debt collection, intercept, revenue maximization and optimization); payroll management for Commonwealth employees (including payroll deductions and tax withholding and reporting); accounting and report management for all Commonwealth assets, liabilities, revenues and expenditures; and communication and training for Commonwealth fiscal officers and users of the state accounting system.

The Comptroller is assisted by three Deputy Comptrollers who oversee the day-to-day activities, as well as, the long-term initiatives of the Department. There are over 120 full-time equivalent employees in the office, organized into ten bureaus. The Executive Bureau and Resource Management Bureau report directly to the Comptroller, and the other eight bureaus report to the Comptroller through the three Deputy Comptrollers.

The Federal Grant & Cost Allocation Bureau oversees the federal grant and cost accounting activities of Commonwealth agencies. The bureau has two units (Federal Grant Unit & Cost Accounting Unit) and is responsible for a wide variety of financial operational activities.

The Resource Management Bureau’s responsibilities are to provide fiscal management, personnel, payroll and administrative support services for the Comptroller's Office. The bureau records the documents and reports sent to the state library.

The Quality Assurance Bureau (QAB) The Quality Assurance Bureau (QAB) assists in the mission of the Office of the Comptroller by allowing the Comptroller to delegate to departments the approval of low risk transactions. As a result of this delegation, departments are responsible for adherence to regulations, policies and procedures for all of their fiscal business. The QAB’s four areas of responsibility are: Quality Assurance Reviews, Internal Controls, statewide Single Audit, and Comptroller Internal Audit.
The Financial Reporting and Analysis Bureau (FRAB) is responsible for all financial reporting and analysis functions at the Office of the State Comptroller. Reports prepared by FRAB include: Statutory Basis Financial Report, and Comprehensive Annual Financial Report.
 
The Department Assistance Bureau, the "Customer-Service" bureau in the Comptroller's Office, provides a number of services, including: training and ongoing support for state employees on MMARS, LCM, the Information Warehouse, Payroll Procedures, and Internal Controls. DAB provides technical assistance to MMARS and LCM users via a central helpline network, web portal maintenance, and oversight of application security for MMARS and LCM.
 
The Accounts Payable Bureau is responsible for the review, approval, management and maintenance of the Commonwealth Vendor/Customer table. It oversees all payments issued through the Massachusetts Management and Reporting System (MMARS), and manages all matters regarding tax reportable income reported to the Internal Revenue Service, Social Security Administration and/or Massachusetts Department of Revenue. It also carries out oversight of all contracts, encumbrances, grants, subsidies, and Intergovernmental Service Agreements (ISAs) processed through the Massachusetts Management and Reporting System (MMARS), and oversees the coordination and updating of the Expenditure Classification Handbook and the FY Closing/Opening Instructions.
The General Accounting Bureau oversees the accounting activities of the Commonwealth and provides guidance to departments. The bureau is comprised of three units: Accounts Receivable/e-Commerce, Budgetary and Reconciliation. Together, these units manage the collection of non-tax revenue and debt-collection, and manage various Commonwealth funds, accounts, and reconciliations.

The Enterprise Systems Serviceprovides information technology services that support both the day-to-day business and the future direction of the Office of the Comptroller. These services include: maintenance of the Comptroller's Intranet/Internet sites, enterprise-wide applications operations, maintenance and enhancement support, and strategic project planning and coordination.
 
The Payroll Bureau The Payroll Bureau is responsible for ensuring that the Commonwealth payroll system, HR/CMS, pays all Employees/Contracted Employees on-time, accurately and efficiently. In addition, the Payroll Bureau (PRB) ensures the departments post payroll expenditures within available budgets and to accounts suitable for such charges.

PRB implements Commonwealth payroll policies, coordinating consistent implementation with both the University payroll system, e*mpac, and the Sate Payroll system, HR/CMS. The PRB accomplishes these functions by ensuring Payroll systems are reliable and properly maintained, policy is clear and well distributed, reports are available and accurate, and departmental payroll professionals are continually updated and given the tools needed to do their jobs.