Prior-year budgeting
Building next year's numbers by adjusting this year's, instead of starting over
Prior-year budgeting, also called incremental budgeting, starts from the current year's budget or actual spending and adjusts each line by an increment, rather than justifying every line from zero. It is faster to prepare than zero-based budgeting, but it also carries forward whatever went unexamined last year, including chronic underbudgeting.
How it works
Most HOA operating budgets are built this way by default. Take last year's approved budget, or last year's actual spending, and adjust each line by a percentage or a dollar amount for the year ahead. That is incremental budgeting, the opposite of zero-based budgeting, which discards last year's number and asks every line to be justified again from scratch.
"the budget is prepared by taking the current period's budget or actual performance as a base, with incremental amounts then being added for the new budget period."
Source: Comparing budgeting techniques (Incremental v ZBB), Association of Chartered Certified Accountants
The tradeoff: speed against blind spots
Incremental budgeting is quicker and cheaper to prepare than zero-based budgeting, and it is easy to delegate: a manager can adjust a dozen lines by a percentage without defending every dollar to the board. It also shows the effect of a single change fast; raise the insurance line by a set amount and the total moves with it.
The cost runs the other way. Any inefficiency, stale assumption, or quiet shortfall built into last year's number rides along unexamined into next year's, because nothing in the method requires anyone to ask whether the base figure was ever right.
Where it hides trouble
Prior-year budgeting can mask two different problems. First, if a line was underfunded last year, nudging it up by the same small percentage keeps it underfunded this year too. A national reserve-study firm has reported that most of the associations it studies come up short against their reserve components, a gap a reserve study is meant to surface, though that figure comes from one firm's own client base and is not a verified national number.
Second, a line copied forward from last year's budget, and never checked against what actually got spent, can drift from reality for years. Comparing a line to last year's actual spending, not only to last year's budgeted amount, is the check that catches drift before it turns into a special assessment.
Whether your association's annual budget report must explain a year-over-year increase, or disclose a funding shortfall, to members varies by state statute and by your governing documents. Check your state's common-interest-community law and your own bylaws before assuming a disclosure duty does or does not apply.
Check yourself
Answer before you read the explanation, recalling it is what makes it stick.
The board takes last year's landscaping line, adds a flat 3 percent for cost increases, and moves on without reviewing usage. Which budgeting method is this?
What's the biggest risk of building every year's budget from last year's numbers?
A treasurer worries that prior-year budgeting is hiding chronic underbudgeting. What check catches it?
- Comparing budgeting techniques (Incremental v ZBB), Association of Chartered Certified Accountants
- California Civil Code Section 5300, Annual Budget Report, State of California
- 2026 HOA Reserves Industry Insights Report, Association Reserves
Budgeting
Curious what building from zero looks like instead? See how zero-based budgeting forces every line to earn its place.
Whether your association's annual budget report must explain year-over-year increases, and how much detail it must disclose, varies by state statute and by your governing documents.