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Home-State 529 vs. Utah My529 vs. Taxable Savings: The $25,443 Gap for Two Kids as September 2026 CD Rates Start Falling

Here's the question that lands in every parent's inbox eventually: home-state 529, out-of-state 529 like Utah My529, or just park the money in a CD and skip the paperwork? The honest answer is "it depends on your state tax rate" — but nobody wants to hear that without seeing what "depends" actually costs. So let's run it.

The Scenario: Two Kids, One September 2026 Snapshot

Picture a family with two kids — one 15 years from college, one 10 years out — contributing $250/month per child ($3,000/year each, $6,000/year combined). They're deciding among three paths:

  1. Home-state 529 plan — 0.82% average expense ratio, state income tax rate of 5%, joint-filer deduction cap of $10,000/year on contributions
  2. Utah My529 — 0.12% average expense ratio, no state deduction (they don't live in Utah)
  3. Taxable savings/CD account — currently yielding around 4.0%, taxed annually at a 24% marginal federal bracket

The Bureau of Labor Statistics' August 2026 release puts CPI at +0.4% for the month and unemployment at 4.1%, with payroll growth of just +162,000. That's a cooling-but-not-collapsing labor market — the kind that typically pulls short-term rates (and CD yields) down over the following year. NerdWallet's September 18 mortgage rate check confirms the broader rate environment is holding steady for now, not climbing. Translation: the "safe" CD option isn't getting safer in yield terms — it's likely to get worse, right as inflation keeps nudging college costs upward.

This is exactly the kind of moment where "just pick the plan with no fees" or "just use a CD, it's guaranteed" stops being good enough advice. You can model this for your specific situation at Nelovanti — but here's what the math looks like for this example family.

The Three Options, Side by Side

PlanExpense RatioState DeductionNet Assumed Return
Home-state 5290.82%5% on $6,000 = $300/yr6.18%
Utah My5290.12%None (out-of-state)6.88%
Taxable CD account0% (but taxed annually)N/A3.04% after-tax

We're using a 7% gross market return assumption for the 529 age-based portfolios — a standard planning assumption, not a guarantee — minus each plan's expense ratio. For the taxable account, we're using a 4.0% CD yield taxed at 24% federal, which nets out to roughly 3.04% after tax, since CD interest is taxed as ordinary income every single year, not deferred like 529 growth.

Running the Numbers: Child by Child

Older child (15 years to enrollment), $3,000/year contributed:

  • Home-state 529 (before deduction credit): $70,800
  • Utah My529: $74,670
  • Taxable CD account: $55,980

Younger child (10 years to enrollment), $3,000/year contributed:

  • Home-state 529 (before deduction credit): $39,915
  • Utah My529: $41,202
  • Taxable CD account: $34,449

Combined, both kids:

  • Home-state 529 (before deduction credit): $110,715
  • Utah My529: $115,872
  • Taxable CD account: $90,429

Before we even add in the state deduction, Utah My529's lower expense ratio is worth $5,157 more than the home-state plan over this horizon — purely from the fee gap compounding for 10-15 years. That's consistent with what we found in Home State 529 vs. Utah My529 vs. High-Fee Plans: The $39,000 Gap — expense ratios matter more the longer the money sits.

This is the kind of analysis Nelovanti runs for you — so you don't have to build the spreadsheet yourself.

The Real Swing Factor: Your State Tax Rate

Now add back the home-state deduction. At a 5% state tax rate on the full $6,000 combined contribution, the family saves $300/year in state taxes. Invested at the same after-tax rate as the taxable account (3.04%) over an average 12.5-year horizon, that tax savings compounds to roughly $4,484.

Add that to the home-state total: $110,715 + $4,484 = $115,199.

Compare that to Utah My529's $115,872, and Utah still wins — but by only $673. That's a razor-thin margin, and it flips easily depending on three variables specific to your household:

  • Your actual state tax rate. At a 5.75% state rate instead of 5%, the home-state plan's deduction benefit grows to roughly $345/year, which is enough to erase Utah's lead entirely and put the home-state plan slightly ahead. A lot of states sit in that 5-6% range, so this isn't a hypothetical edge case — it's the actual decision point for a large share of families.
  • Your state's deduction cap. We assumed a $10,000 joint-filer cap, which comfortably covers the family's $6,000 in annual contributions. Some states cap deductions at $4,000-$5,000 combined, which would shrink the tax-savings benefit and push the verdict further toward Utah.
  • Whether your state offers a deduction at all. Nine states currently offer no state income tax deduction for 529 contributions regardless of which plan you use — in that case, the home-state plan loses its only advantage and the expense-ratio gap decides everything.

We walked through this same break-even logic with a different set of assumptions in 529 Plan State Tax Deductions: The $2,000/Year Savings Most Parents Miss, and the conclusion holds here too: the deduction is worth running the actual numbers on, not assuming.

Why the Taxable Account Falls Behind in This Rate Environment

The gap between either 529 option and the taxable CD account is the least ambiguous part of this comparison: $25,443 between Utah My529 and the taxable account, $24,600 between the home-state plan and the taxable account.

Two things widen that gap specifically in September 2026's environment:

First, tax-deferred compounding matters more when yields are falling. A CD paying 4.0% today is already getting taxed away to a 3.04% net return. If the Fed responds to the cooling labor market (4.1% unemployment, +162,000 payrolls — both softer than a hot economy) by cutting rates over the next 12-18 months, new CD offers could easily drop to 3.5% or lower, while 529 growth assumptions stay anchored to long-run equity market returns rather than short-term rate cycles.

Second, the annual tax drag compounds against you every single year, not just once. A 529 account defers all of that until qualified withdrawal (and often avoids it entirely for education expenses), while a taxable CD account hands a chunk of your gains to the IRS annually, shrinking the base that compounds going forward. We ran a similar comparison with different starting numbers in 529 vs. Taxable CD Calculator: The $98,822 Gap for a Two-Kid College Fund, and the pattern is consistent: the gap only grows with time horizon and contribution size.

What Would Change the Verdict

None of this means Utah My529 (or any specific out-of-state plan) is automatically right for you. A few things could flip this analysis:

  • A higher home-state deduction or tax rate closes the gap fast, as shown above — it doesn't take much.
  • A shorter time horizon shrinks the compounding advantage of the lower expense ratio, since there's less time for 0.70 percentage points of annual fee difference to add up.
  • Multi-child coordination changes the math — if you're funding three or four kids instead of two, or staggering contributions unevenly by age, the expense-ratio advantage compounds differently for each child's individual timeline, and the household-level deduction cap gets split (or maxed out) differently too.
  • A market downturn near enrollment affects both 529 options similarly but doesn't touch the taxable CD at all — which is a real risk-tolerance factor this analysis doesn't fully capture with a flat 7% assumption.

If you're weighing this decision against other uses for that same $500/month — extra mortgage payments, for instance — the math shifts again depending on current mortgage rates, which NerdWallet's tracker shows holding steady this week. We covered that specific trade-off in Utah My529 vs. Home-State 529 vs. Extra Mortgage Payments: The $4,460 Gap When September 2026 Rates Rise.

Your Numbers Will Differ

The example above uses a 5% state tax rate, a $10,000 deduction cap, two kids with specific age gaps, and a 7% market return assumption. Change any one of those — your actual state's tax bracket, your real contribution amount, your kids' actual ages, or a more conservative return assumption — and the $673 Utah advantage could become a $2,000 home-state advantage just as easily.

That's the whole point of running this as a calculation rather than a rule of thumb. "Utah My529 is always cheaper" and "always use your home-state plan for the deduction" are both wrong often enough to matter. The right answer is the one that comes out of your specific state tax rate, your specific kids' timelines, and your specific contribution plan.

You can plug in your own numbers — your state, your tax bracket, your kids' ages, your contribution amount — and get the actual verdict for your household at Nelovanti, instead of guessing from a stranger's example.

Sources

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