What is a 529 plan?

The average cost of four years at an in-state public university is now over $100,000. At a private school, it’s closer to $240,000. Whether those numbers will be higher or lower in 18 years is uncertain. What isn’t uncertain: money invested in a 529 today grows tax-free and comes out tax-free for qualified education costs. That’s a structural advantage worth using.

A 529 plan is the main tax-advantaged account for education savings in the US. You contribute after-tax dollars, the money grows tax-free, and qualified education withdrawals come out tax-free. Many states sweeten the deal with a state income tax deduction for contributions.

Used well, a 529 turns roughly $100,000 of contributions into $200,000+ of tax-free education spending over 18 years. Used badly, it locks up money you could have used more flexibly.

The tax structure

Three tax layers, each independent:

1. Federal income tax: no deduction for contributions. Growth is tax-deferred. Qualified withdrawals are tax-free.
2. State income tax: most states offer a deduction or credit for contributions to their state’s plan (some allow any state’s plan). Check your state’s specific rule — the deduction can be worth $200–$1,000+ per year depending on state and contribution size.
3. Gift tax: contributions count as gifts to the beneficiary. You can contribute up to the annual gift exclusion (~$18,000 per donor, per beneficiary in 2024) without paperwork, or “superfund” up to 5 years at once ($90,000) with a one-time election.

There is no federal income limit on who can contribute. High earners priced out of Roth IRAs can still use a 529.

What “qualified expenses” actually include

The list is broader than most people realize:

• Tuition and fees at any accredited college or university (including many abroad)
• Room and board up to the school’s published cost-of-attendance, for students enrolled at least half-time
• Books, supplies, computers, software, and internet required for enrollment
• Up to $10,000/year per student for K-12 tuition (public, private, or religious)
• Up to $10,000 lifetime to pay off student loans for the beneficiary (and separately $10k for each sibling)
• Apprenticeships registered with the Department of Labor
• Special-needs services if required for attendance

What’s not qualified (triggers tax + 10% penalty on earnings):

• Transportation (even to/from campus)
• Health insurance premiums
• Room and board for less-than-half-time students
• Non-required computers or equipment
• Cell phones

Growth projection

A 529 works best with early, consistent funding. Two scenarios, each targeting $150k at age 18 (reasonable in-state public college total):

• Start at birth, 7% growth: $340/month
• Start at age 10, 7% growth: $1,060/month

Starting 10 years later triples the required monthly contribution. This is the cost-of-waiting problem applied to a hard deadline — and unlike retirement, you can’t push the deadline back.

The plan menu (and picking a good one)

Every state sponsors at least one 529 plan; some sponsor multiple. You are not required to use your own state’s plan — but if your state offers an income-tax deduction, it’s usually tied to contributions to the in-state plan.

Quality criteria:

1. Low expense ratios. The best index-based 529 plans charge 0.05–0.15%. The worst active-management 529 plans charge 1%+. That difference compounds over 18 years.
2. Age-based glide paths. Most plans offer target-date-style portfolios that automatically shift from stocks to bonds as the beneficiary approaches college age.
3. State-tax deduction. If meaningful in your state, this can outweigh a small expense-ratio disadvantage.

Widely-recommended national choices: Utah’s my529, Nevada’s Vanguard plan, New York’s 529. These tend to top Morningstar and Saving For College rankings year after year.

The “what if the kid doesn’t go to college?” problem

The biggest objection to 529s is flexibility. What if your beneficiary doesn’t need the money? The options are better than most people assume:

• Change the beneficiary to any other family member (sibling, cousin, yourself, your future grandchild). Unlimited and tax-free.
• Roll up to $35,000 lifetime into a Roth IRA for the beneficiary. New rule as of 2024 (SECURE 2.0). Account must have been open 15+ years, contributions from the last 5 years can’t roll, and the beneficiary must have earned income.
• Non-qualified withdrawal. Pay tax + 10% penalty on the earnings portion only (contributions come out tax-free and penalty-free).
• Scholarship exception. If the beneficiary receives a scholarship, you can withdraw up to the scholarship amount penalty-free (still owe tax on earnings).

A common family pattern: start a 529 aggressively while kids are young, slow contributions in their teens once college trajectory is clearer, and use the beneficiary-change and Roth rollover options as safety valves for over-funding.

529 vs. the alternatives

Account	Tax on growth	Tax on withdrawal	Flexibility
529	None	None if qualified	Education-focused; limited escape hatches
UTMA/UGMA	Ordinary/capital gains	Ordinary/capital gains	Fully flexible; child owns at age of majority
Taxable brokerage (in parent’s name)	Annual tax	Capital gains	Fully flexible
Roth IRA	None	Tax-free if over 59½	Contributions withdrawable any time

Go with a 529 as your primary vehicle for college savings. UTMA/UGMA (custodial) accounts hand full control to the child at 18–21, which tends to come as a surprise. Taxable brokerage doesn’t match 529’s tax benefits, but wins on flexibility if you’re genuinely unsure the money will be used for education.

Roth IRAs are a stealth college vehicle for some families: contributions can be withdrawn penalty-free any time for any reason, and the account remains a retirement asset if never needed for college.

Financial aid implications

A 529 owned by a parent counts as a parent asset on the FAFSA. Parent assets are assessed at a maximum 5.64% rate in the Expected Family Contribution formula — i.e. $10,000 of 529 savings reduces need-based aid by up to $564.

A 529 owned by a grandparent used to be reported as student income (assessed at up to 50%), but the FAFSA Simplification Act (effective 2024–25 academic year) removed this penalty. Grandparent 529s are now financial-aid-friendly.

The starter playbook

1. Pick a plan. In-state for the tax deduction, otherwise a low-cost national plan.
2. Choose an age-based portfolio. Let the glide path handle rebalancing.
3. Automate contributions. Match to your pay schedule — even $100/pay period compounds.
4. Increase with raises. A 529 is among the first places to direct bonus and raise dollars.
5. Don’t over-fund. Aim for in-state public college costs; use the rollover and beneficiary-change rules as flexibility rather than over-saving.

Further reading

• Savings Goal calculator — size monthly contributions for a target education amount
• Compound Interest calculator — the 529’s tax-free growth mechanic in interactive form
• Cost of Waiting calculator — why starting at birth is so much cheaper than starting later
• Saving For College: 529 plan comparison and ratings