Budget object classification codes are standardized numerical identifiers the federal government uses to categorize every dollar of obligations by the type of good or service purchased. The Office of Management and Budget defines them in Section 83 of OMB Circular A-11, and federal law at 31 U.S.C. 1104(b) requires the President’s Budget to present obligations using them.1Office of the Law Revision Counsel. 31 USC 1104 – Budget and Appropriations Authority of the President The system gives Congress, analysts, and the public a consistent way to see whether federal funds went toward salaries, contracts, equipment, grants, or other categories, no matter which agency spent the money.
What the Codes Actually Tell You
Object class codes answer one question: what did the government buy? They track the type of item or service, not the agency that bought it or the program it supports. A salary at the Department of Defense and a salary at the Department of Education fall under the same personnel compensation code, even though they fund entirely different missions.
That is the opposite of how most people think about federal spending. Budget debates usually center on programs and purposes: how much for defense, how much for healthcare, how much for education. Object classes cut across all of that. They let anyone ask questions like how much the entire government spends on rent, or what share of total spending goes to contracts versus in-house employees. Program-level data alone cannot answer that.
Classification follows a firm rule. You categorize based on what the government is initially buying, not what the purchase ultimately produces. If a federal employee builds a road, the obligation is personnel compensation, because the government is paying a worker’s salary. If a contractor builds the same road, it is contractual services. The end product is identical; the object class reflects how the money was spent.
How a Code Is Built
Each code has two parts. The first two digits identify the major category, such as 10 for personnel costs or 20 for contractual services. A decimal digit narrows the classification. Code 11.1, for example, means full-time permanent personnel compensation: “11” places it in the personnel compensation group, and “.1” specifies full-time permanent employees rather than temporary or part-time staff.
OMB defines the standard codes and titles that every agency must use when submitting budget data through the MAX A-11 system. Agencies have some flexibility inside that framework. An agency can insert additional lines under a standard object class to break out more detail. For instance, an agency could split code 21.0 (travel) into separate lines for employee travel and grantee travel, editing the standard titles to reflect the split. That keeps OMB-level reporting consistent while giving agencies internal granularity.
The Five Major Categories
All federal obligations sort into five major groups. Each covers a fundamentally different type of spending.
10 Series: Personnel Compensation and Benefits
This series captures everything the government pays its workforce. Code 11.1 covers full-time permanent civilian salaries, 11.3 covers part-time or temporary employees, and 11.7 covers military personnel pay. Code 12.1 covers civilian benefits such as the employer’s share of retirement contributions and health insurance, and 12.2 covers military benefits. Code 13.0 picks up benefits paid to former employees or their survivors, including pensions tied to length of federal service.
20 Series: Contractual Services and Supplies
This is the broadest category. It covers virtually all non-personnel operating costs where the government acquires goods or services from outside sources. Code 21.0 covers employee travel, 22.0 covers shipping and transporting goods, 23.1 covers rent paid to the General Services Administration, 23.2 covers rent paid to non-federal landlords, and 23.3 covers communications and utilities. Codes 25.1 through 25.8 cover advisory, consulting, engineering, and other professional services. Code 26.0 handles supplies and materials consumed in operations.
30 Series: Acquisition of Assets
This series covers capital purchases, where the government acquires tangible property. Code 31.0 applies to equipment, and 32.0 applies to land and structures. When a federal agency buys a building outright, the obligation falls here rather than under contractual services, because the government is acquiring a long-term asset instead of buying an ongoing service.
40 Series: Grants and Fixed Charges
This category captures payments that do not directly support federal operations but are fixed by law or flow outward to other entities. Code 41.0 covers grants, subsidies, and contributions, which is how much of the federal government’s spending on state programs, research grants, and foreign aid gets classified. Code 42.0 covers insurance claims and indemnities.
90 Series: Other
This residual category catches obligations that do not fit the other four groups. Code 91.0 covers unvouchered expenditures, which are charges that can be incurred for confidential purposes without detailed reporting. Code 92.0 covers undistributed obligations that agencies cannot assign to a standard object class; using this code requires prior OMB approval. Code 94.0 handles financial transfers between federal accounts that do not represent an exchange of goods or services.
Object Class Versus Budget Function
People often mix up object class codes with budget function codes, but the two organize spending along different dimensions. Budget functions group spending by purpose, sorting all federal activity into broad mission areas such as national defense, health, or income security. Object classes ignore purpose entirely and focus on what the government actually purchased.
A computer bought for the Department of Veterans Affairs and one bought for NASA would fall under different budget functions (veterans’ benefits versus space exploration) but the same object class (equipment). The two systems complement each other. Budget functions tell you why the government spent money; object classes tell you how.
Where to Find Object Class Spending Data
Federal agencies submit object class data to OMB as part of their annual budget formulation, using the formats set out in Circular A-11 and the MAX system. Every proposed obligation must be mapped to the correct code before an agency’s budget justification is complete. Agencies also report financial data to the Treasury through the Governmentwide Treasury Account Symbol Adjusted Trial Balance System, which collects both proprietary financial information and budget execution data from all federal entities.2Bureau of the Fiscal Service. Governmentwide Treasury Account Symbol Adjusted Trial Balance System
You do not need to read budget appendices to see the results. USAspending.gov, the government’s official spending transparency site, lets anyone explore federal obligations grouped by object class through its Spending Explorer tool.3USAspending.gov. Government Spending Explorer You can see how much went to personnel compensation versus contracts versus grants across the entire government or within a single agency. For oversight, journalism, or policy research, it is the fastest way to answer the cross-cutting spending questions that program-level data cannot.