“The best time to build lifelong money habits is when you are young. The second-best time is today.”
Investing 104
Roth IRA, 401(k), HSA, 529 — and the order to fund them. Every dollar of tax you avoid compounds for decades.
The same income, invested in the same funds, produces dramatically different wealth depending on which accounts hold it. Most people treat taxes as something that happens to them. This lesson treats the tax code as what it actually is — a system with levers you are allowed to pull in your favor, legally, starting now.
Those levers are the tax-advantaged accounts: the 401(k), IRA, Roth IRA, HSA, and 529, each of which trades a rule you have to follow for tax you never have to pay. What follows is every one of them a normal family will actually use, what the 2026 limits are, and the order to fill them.
This lesson pairs with Building a Portfolio — that one covers what to own; this one covers where to hold it. For the broader tax picture beyond accounts, see Tax Strategies.
On This Page
Every investment account you will ever own falls into one of three tax treatments:
None of the three is “best.” They are tools with different shapes, and the families who build real wealth typically end up holding all three on purpose — a point we return to at the end.
The employer-plan landscape — 401(k), 403(b), 457(b), SEP and SIMPLE IRAs, Solo 401(k)s, pensions, ESPPs — was covered in Investing for Retirement. Here is the tax-treatment view of the accounts most families actually use, with 2026 limits:
| Account | 2026 Limit | Tax Treatment | The One Thing to Know |
|---|---|---|---|
| 401(k) / 403(b) / 457(b) / TSP | $24,500 (+$8,000 catch-up at 50+; $11,250 at 60–63) | Traditional or Roth | The employer match is an instant 50–100% return. Always capture all of it. |
| Traditional IRA | $7,500 (+$1,100 at 50+) | Tax-deferred | Deductibility phases out at higher incomes if you also have a workplace plan. |
| Roth IRA | $7,500 (+$1,100 at 50+), shared with Traditional | Tax-free | Contributions (not earnings) can be withdrawn anytime, penalty-free — less scary than it sounds. |
| HSA | $4,400 individual / $8,750 family (+$1,000 at 55+) | Triple-advantaged | Requires a qualifying high-deductible health plan. See below — it may be the best account in the entire code. |
| 529 plan | No federal annual limit (gift-tax rules apply) | Tax-free for education | Now covers $20,000/year of K-12 costs, and up to $35,000 of leftovers can roll to your child’s Roth IRA — a few thousand a year, not all at once. See below. |
| Taxable brokerage | Unlimited | Taxable | The flexibility layer. Long-term gains rates reward holding more than a year. |
Two wrinkles worth knowing before you set your contributions. The catch-up gets bigger for four years. Between 50 and 59 it is $8,000 on top of the $24,500; at 60, 61, 62, and 63 it jumps to $11,250, then drops back to the ordinary amount at 64. Those four years are the largest tax-deferred window the code ever gives you, and they arrive exactly when most people are finally able to use them.
Roth IRAs phase out by income. For 2026 the ability to contribute directly narrows between $153,000 and $168,000 for single filers and heads of household, and between $242,000 and $252,000 for married couples filing jointly — above the top of each range, direct contributions are off the table entirely. That is what the backdoor Roth below exists to work around.
Limits change almost every year — verify the current numbers at IRS.gov before you set your contributions each January.
The entire Traditional-versus-Roth debate reduces to one question: is your tax rate higher today, or will it be higher when you withdraw? Pay the tax in whichever era it is cheaper.
The Health Savings Account is the only account in the tax code with all three advantages at once: contributions go in pre-tax, growth is untaxed, and withdrawals for qualified medical expenses come out untaxed. Tax-deferred accounts give you the first two; Roth gives you the last two; the HSA alone gives you all three.
The strategy that turns it into a retirement account: if your budget allows, pay today’s medical bills out of pocket while you are young and healthy, and let the HSA balance stay invested — most providers let you invest it in the same low-cost index funds as any other account. The balance then compounds untouched for decades, arriving exactly when healthcare costs peak: retirement. After 65, non-medical withdrawals are simply taxed like a Traditional IRA, so there is no scenario where diligent HSA savings get stranded.
The requirement is being enrolled in a qualifying high-deductible health plan, which is a genuine trade-off if your family has high recurring medical costs — run your own numbers during open enrollment rather than defaulting either way.
Everything above has a parallel track for your children, and the early years are where tax-free compounding does its most spectacular work:
The full layering strategy — which account at which age — is covered in the Childhood Foundations and Teen & College guides.
When the paycheck cannot fund everything — and most paychecks cannot — order matters. This is the waterfall our family uses, and the logic is simple: free money first, then tax-free growth, then flexibility.
Steps 1 through 3 are achievable for most households well before high income arrives. Do not let the length of the list discourage you — the first step alone puts you ahead of the majority of savers.
There is a final reason to fund all three buckets rather than optimizing for one: flexibility at the far end. A retiree holding tax-deferred, tax-free, and taxable money can choose, every single year, which bucket to draw from — filling the low tax brackets with Traditional withdrawals, topping up from Roth without raising taxable income, harvesting taxable gains in the 0% bracket years. A retiree with everything in one bucket takes whatever tax treatment that bucket dictates, in every year, forever.
You cannot know what tax rates will be in thirty years. Holding all three buckets is how you stop needing to know.
The portfolio from the previous lesson determines what your money earns. The accounts on this page determine how much of it you keep — and over forty years of compounding, the keeping is frequently worth more than the earning. Capture the match this month. Open the Roth this year. Start the 529 clock the year each child is born. None of these levers requires wealth to pull — only the decision to pull them early.
Continue to Tax Strategies for the rest of the tax picture, or return to Building a Portfolio.