A budget model that requires detailed justification of all line items is called?

Zero-based budgeting is a financial planning method that requires every line item of the budget to be justified for each new period, rather than using the previous period's budget as a starting point. This means that all expenses must be approved rather than only the changes in expenditures, which often leads to a more systematic evaluation of needs and costs. Each department or unit must present a detailed explanation of why they require funding for each aspect of their operations, promoting accountability and careful consideration of expenses.

This approach contrasts with other budgeting methods, where previous budgets may simply be adjusted incrementally or where cuts may be made based on predetermined ceilings without thorough justification of every expense. Zero-based budgeting encourages organizations to think critically about their spending and align it closely with current goals and priorities.