The oldest type of budget is referred to as an appropriation budget. Appropriation budgets place a maximum limit on certain discretionary expenditures and may be either incremental, priority incremental, or zero based. Incremental budgets are essentially last year’s budget amount plus an increment, i.e., small increase. Priority incremental budgets also involve an increase, but require managers to prioritize, or rank discretionary activities in terms of their importance to the organization. The idea is for the manager to indicate which activities would be changed if the budget were increased or decreased, Zero based budgeting was popular but was dropped by most users because it was too expensive and time consuming. The technique is expensive to use because zero based budgets theoretically require justification for the entire budget amount.
From a control perspective, appropriation budgets are effective in limiting the amount of expenditure, but create a behavioral bias to spend to the limit. Establishing a maximum amount for an expenditure encourages spending to the limit because spending below the limit implies that something less than the maximum appropriation was needed. Spending below the limit might result in a budget cut in future periods. Since nearly every manager views a budget reduction in their discretionary costs as undesirable, there are frequently crash efforts at the end of a budget period to spend up to the limit.
 Flexible Budgets
Flexible budgets are based on a cost function such as Y = a+ bX, where Y represents the budgeted cost, or dependent variable. The constant “a” represents a static amount for fixed costs and the constant “b” represents the rate of change in Y expected for a unit change in the independent variable X. The expression” bX” is the flexible part (variable) of the budget cost function. The flexible budget technique is used for planning and monitoring all types of costs. The static amount “a” includes both discretionary and committed costs, while the flexible part “bX” includes various types of engineered costs. The flexible characteristic of the technique enables the flexible budget to play a key role in both financial planning and performance evaluation.
2) Capital Budget
Capital budgets represent the major planning device for new investments. Discounted cash flow techniques such as net present value and the internal rate of return are used to evaluate potential investments. Capital budgets are part of a somewhat more encapsulating concept referred to as investment management. Investment management involves the planning and decision process for the acquisition and utilization of all of the organization’s resources, including human resources as well as technology, equipment and facilities. The concept of investment management includes the discounted cash flow methods, but is more comprehensive in that the organization’s portfolio of interrelated investments is considered as well as the projected effects of not investing.
 Master Budgets
The fourth type of budget is referred to as the master budget or financial plan. The master budget is the primary financial- planning mechanism for an organization and also provides the foundation for a traditional financial control system. More specifically, it is a comprehensive integrated financial plan developed for a specific period of time, e.g., for a month, quarter, or year. This is a much broader concept than the first three types of budgeting. The master budget includes many appropriation budgets (typically in the administrative and service areas) as well as flexible budgets, a capital budget and much more.
The master budget has two major parts including the operating budget and the financial budget. The operating budget begins with the sales budget and ends with the budgeted income statement. The financial budget includes the capital budget as well as a cash budget, and a budgeted balance sheet.