Cost of Attendance (COA) in College: What It Means and Why It Caps Your 529

By Kevin Luu, Co-Founder and Chief Learning Officer. Reviewed on 2026-09-30.

In college, COA means cost of attendance: the school’s official estimate of what one academic year costs a full-time student, including tuition and fees, housing and food, books and supplies, a computer, transportation, and personal expenses. It is set by each school under the federal Higher Education Act, and it generally caps the total financial aid a student can receive. For a high-income family that will pay full price, COA matters for a second reason: it caps how much of a 529 withdrawal for housing and food counts as a qualified, tax-free expense.

What cost of attendance includes under federal law

The federal definition lives in 20 U.S.C. 1087ll. Every school that takes part in federal aid builds its COA from the same list:

• Tuition and fees normally charged a student with the same course load.
• Books, course materials, supplies and equipment, including an allowance for renting or buying a personal computer.
• Housing and food. The law now says “food and housing” where schools used to say “room and board.” Allowances differ for students in campus housing, off campus, or living with parents.
• Transportation, including travel between campus, home and work.
• Miscellaneous personal expenses such as a phone, laundry and toiletries.
• Special items where they apply: dependent care, disability-related costs, loan fees, study abroad and professional licensure costs.

Schools must post the elements of their COA on their website. You will usually find several versions for the same school: on campus, off campus and living at home. The differences between them are mostly in housing and food.

What “board” means

“Board” is the old word for meals. “Room and board” means housing plus a meal plan. On a bill you will now often see “housing” and “food” instead, but the idea is the same.

Direct costs vs. indirect costs of attending college

The main difference is who you pay. Direct costs are billed by the school: tuition, required fees, and campus housing and meal plans if the student lives on campus. Indirect costs are real but not billed by the school: books bought elsewhere, a laptop, flights home, off-campus rent, groceries and personal spending.

Two practical consequences follow. First, the school’s bill is always smaller than its COA, so a family that budgets only for the bill will come up short. Second, indirect costs are estimates. Your child’s real spending on travel and off-campus rent can be well above the school’s allowance, especially at a school far from home or in an expensive city.

Why COA matters when you will not qualify for need-based aid

Financial aid offices use a simple formula: COA minus the family’s calculated ability to pay equals need. At household incomes of $750,000 and up, need-based grants are typically unlikely at most schools, so for most readers of this page the COA is close to what four years will actually cost, less any merit scholarship. For how the family contribution side of that formula works, see our guide to expected family contribution.

The federal education credits do not help this family either. For 2025, the American opportunity credit (up to $2,500 per student) is fully phased out once modified adjusted gross income reaches $180,000 on a joint return, according to IRS Publication 970. That leaves the 529 plan as the main tax tool, and that is where COA becomes a tax number.

How COA limits tax-free 529 withdrawals

A 529 withdrawal is tax-free when it pays qualified higher education expenses. Per Publication 970, those include tuition and fees, required books, supplies and equipment, computer equipment and internet access, and housing and food for a student enrolled at least half-time. The housing and food piece has a cap. It qualifies only up to the greater of:

1. the housing and food allowance the school included in its COA for that student’s living arrangement, or
2. the actual amount charged, if the student lives in housing owned or operated by the school.

Two items in the COA are not qualified 529 expenses at all: transportation and general personal spending. If a 529 pays them, the earnings part of that withdrawal is taxed as ordinary income, and Publication 970 adds a 10% additional federal tax on the amount included in income, with exceptions such as withdrawals up to the amount of a tax-free scholarship (the income tax still applies there).

Worked example: a $1.1M Bay Area household planning for a private university

Assumptions, all illustrative: two W-2 parents in San Mateo County earning $1.1M combined, one child age 7, and a private university whose published COA for a student living on campus is $95,000 a year. The split below is invented for the example; use the actual numbers your child’s school posts.

In the on-campus years, the 529 can cover up to $88,300 tax-free. The remaining $6,700 is not a qualified expense, so it is typically paid from cash flow rather than the 529.

Now say the student moves off campus in junior year into an apartment costing $2,400 a month for 12 months ($28,800), plus groceries. If the school’s off-campus housing and food allowance is $21,000 (again illustrative), only $21,000 of rent and food is a qualified 529 expense. The actual-charge rule does not help here, because the landlord is not the school. Paying the full $28,800 plus groceries from the 529 would make everything above the $21,000 allowance a non-qualified withdrawal, with income tax and the 10% additional tax on the earnings portion of that excess.

Over four years at these prices (before any increases), the qualified total is $88,300 x 2 for the on-campus years plus $90,300 x 2 for the off-campus years ($68,000 tuition and fees, $21,000 housing and food allowance, $1,300 books), or $357,200. That figure, not the sticker COA, is the useful funding target for a 529. Costs above it are typically paid from a taxable account or cash.

What this means for how much you put in a 529

Most families at this income do not worry about underfunding a 529. The more common mistake is overfunding it for costs that will never qualify, such as travel, a car or off-campus rent above the allowance. A few points to decide on:

• Target qualified costs, not the full COA. Build the target from tuition, fees and the housing allowance of the kind of school you expect.
• Front-load if it suits your cash flow. For 2026 the gift tax annual exclusion is $19,000 per recipient, and the five-year election lets each parent put up to $95,000 into a child’s 529 at once ($190,000 for a couple splitting gifts), reported on Form 709. See 529 superfunding.
• Know the California wrinkle. California gives no deduction for 529 contributions for 2026 and generally does not conform to the newer federal 529 expense categories added in 2025, so a use that is qualified federally may still be taxable on your California return. Washington has no individual income tax for 2026, so this state layer does not apply there for now. Washington has enacted a 9.9% income tax on AGI over $1 million starting in 2028 (Department of Revenue), and how it will treat 529 withdrawals has not yet been set out.
• Keep a plan for leftovers. Changing the beneficiary to a sibling is usually the simplest option. See transferring 529 ownership, and for money that should stay flexible, 529 plans vs. custodial accounts.

Common mistakes with cost of attendance

• Comparing schools by tuition alone. Housing and food allowances vary widely between a rural campus and one in a major city.
• Using the on-campus COA after the student moves off campus. The off-campus allowance is usually the one that caps the 529.
• Paying flights and personal spending from the 529 because they appear in the COA.
• Withdrawing from the 529 in a different calendar year from when the expense was paid. Match the withdrawal to the expense year and keep the receipts.
• Not checking whether a merit scholarship reduces qualified expenses. A tax-free scholarship does, so the tax-free 529 withdrawal shrinks with it. Publication 970 waives the 10% additional tax (not the income tax) on a withdrawal up to the scholarship amount.

What to write down for your children

A 7-year-old does not need a COA table. A 16-year-old does. The number that changes behavior is not the tuition, it is the gap between what the school charges and what the student spends on everything else. Families we work with often write a short note for each child: what the 529 will pay, what it will not, what they are expected to cover themselves, and why. Written down early, that note turns a college budget into a lesson in how the family thinks about money. We cover this in Age Five Wealth Education.

FAQ

Is cost of attendance the same as tuition?

No. Tuition is one line in the COA. The COA also includes fees, housing and food, books and supplies, a computer allowance, transportation and personal expenses. At a residential private university, the non-tuition items often add a large share on top of tuition, so budgeting for tuition alone understates the real yearly cost.

Where do I find a school’s cost of attendance?

Federal law requires schools to post the elements of their COA on their website, usually on the financial aid or tuition page. Look for separate figures for on-campus, off-campus and living-at-home students, and use the one that matches where your child will live, because that version sets the 529 housing and food cap.

Can a 529 pay for off-campus rent?

Yes, for a student enrolled at least half-time, but only up to the housing and food allowance the school includes in its off-campus COA. Rent and food above that allowance are not qualified expenses, so the earnings portion of any excess withdrawal is taxable and may face the 10% additional federal tax.

Next step

Pull the published COA for two or three schools your family would consider, note the housing allowance for each living arrangement, and compare the qualified total with what your 529 is on track to hold. If you want help setting that target alongside your equity compensation and estate plan, the Tax & Wealth Assessment is where we start.

This is general education, and the right move depends on your family’s full picture. Related reading: how schools set their cost of attendance and estate planning for families with young children.

Written by

Kevin Luu

Co-Founder and Chief Learning Officer, Bright Advisers

Kevin has advised high-income W-2 tech and biotech families since 2015, and leads the education-first Age Five Family Office from Brea, California.

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