College costs run somewhere between $25K/year (in-state public) and $90K/year (elite private) in 2026 dollars. With 5-6% annual education inflation, the kid born today faces $90K-$320K total over a 4-year program. Most calculators stop at “save $X/month at 7% to reach this number.” That ignores the strategic choices that change the answer by tens of thousands of dollars.
Grandparent-owned vs parent-owned 529. This is the most under-appreciated decision. Pre-2024, a grandparent-owned 529 had no impact on FAFSA assets but distributions counted as student income (50% of which was assessed against aid). Post-2024 FAFSA simplification removed the income-test entirely for grandparent distributions. Net result: a grandparent-owned 529 now has essentially zero impact on need-based aid, while the same money parent-owned reduces aid by 5.64% of the balance per year. For a $100K balance, that's $5640/year less aid for 4 years = $22,560 cost. Asking grandparents to be the account owner (or transferring ownership before college) can be worth tens of thousands.
SECURE 2.0 Roth conversion (new 2024). The biggest 529 fear has historically been “what if my kid doesn't go to college?” Until 2024, unused 529 funds withdrawn for non-education purposes triggered tax + 10% penalty on growth. Now: up to $35K lifetime per beneficiary can roll to a Roth IRA. The account must be 15+ years old, and rollovers count against the kid's annual Roth contribution limit (~$7K/yr in 2026). It's not unlimited, but it removes the catastrophic downside of over-funding.
The retirement trade-off is real. Every dollar you put into a 529 is a dollar you're not putting into your own retirement. The math: if you're in a 24% bracket and contribute $300/month to a 529 instead of a 401(k), you're giving up $72/month in tax savings and the future compound growth on your own savings. For families that haven't maxed retirement accounts and don't have certainty about college paths, this often argues for retirement-first, education- later — kids can borrow for college, you can't borrow for retirement.
Financial aid math is non-obvious. The Student Aid Index (SAI, replaced EFC in 2024) determines how much aid you might qualify for. It uses a complex formula weighing parental income (most heavily), parental assets (5.64% counted), student income (heavily, beyond a $9K protection allowance), and student assets (20% counted). For most middle-to-upper-middle income families, expected family contribution exceeds total college costs at most schools — meaning no need-based aid regardless of strategy. For lower-income families, asset-positioning matters enormously.