Every building stands on pillars. Remove one and the structure leans. Remove two and it falls. Your path to financial independence works the same way.
I think of my accounts as pillars that hold up my FIRE, each with its own job. Cash keeps me from selling in a crash. The 401(k) gives me a tax break now. The HSA pays for healthcare without tax. The Roth is money that's never taxed again. And the taxable brokerage account is the bridge I'll live on before 59½.
Underneath all five pillars is a foundation: spend less than you earn, automate your saving, and carry no high-interest debt. Without that foundation, no pillar stands for long.
The pillars are simple enough to name. The harder question is which one to build first, how much to pour into each, and when to shift your weight from one to another. That's where the fill order comes in: a step-by-step sequence I pieced together, adjusted, and now teach. It grew with me from a single 401(k) in 2011 to four kinds of tax-advantaged accounts by 2023, and it can do the same for you.
The Five Pillars
Cash. Your emergency fund while you work, and two years of living expenses once you stop, enough to ride out a bear market without selling stocks at a loss. It doesn't compound like stocks, but it keeps you from selling during a downturn, and that protection is worth more than any return you'll miss by holding it.
The 401(k). Your employer-sponsored retirement account gives you a tax deduction and often comes with a match, free money you can't get anywhere else. I'll convert mine to Roth step by step during the low-tax years after I stop working, as part of my zero-tax retirement plan.
The HSA. If you have a high-deductible health plan, the HSA is the only account with a triple tax advantage: contributions are deducted, growth is tax-free, and qualified medical withdrawals are tax-free. After 65, it works like a traditional IRA for non-medical expenses, so nothing you put in is ever wasted.
The Roth. Money in a Roth IRA or Roth 401(k) has already been taxed. It grows tax-free and comes out tax-free. If your income is too high, the backdoor Roth gets you in anyway.
The taxable brokerage account. No contribution limits, no age restrictions, no penalties for withdrawal. I keep the same low-cost index funds there that I hold in my 401(k) and HSA. This is the account early retirees need most because you can spend from it before 59½ without the 10% penalty on most 401(k) withdrawals.
What Feeds the Pillars
Two things feed the pillars rather than being pillars themselves. The ESPP lets you buy company stock at a discount. I sell every purchase as soon as it settles to capture the discount without single-stock concentration risk, and move the money into the pillars. Equity pay like RSUs works the same way: sell when it vests, reinvest. Pre-IPO shares don't count until they can be sold.
What Sits Outside
Rentals sit outside the pillars. Their rent covers part of my spending, so I need a smaller FIRE number. I own long-term and short-term rentals, and their income reduces what my pillars need to support.
Our kids' accounts sit outside too. They're for teaching the kids, not part of my FIRE, and they get funded only after my own pillars.
The Pillars That Hold Up Your FIRE
┌──────────────────────────────────────────────────────┐
│ 🔥 YOUR FIRE 🔥 │
└──────────────────────────────────────────────────────┘
│ Cash │ 401(k) │ HSA │ Roth │ Taxable │
│ │ │ │ │ Broker. │
│ E.F. │ Tax │ 3x │ Tax- │ No age │
│ while │ break │ tax │ free │ rules │
│ work; │ now; │ adv. │ for- │ No │
│ 2 yrs │ Roth │ │ ever │ limits │
│ when │ conv. │ │ │ │
│ done │ later │ │ │ │
──┴────────┴─────────┴──────┴───────┴─────────┴──
FEEDERS: ESPP + Equity Pay → sell → reinvest
OUTSIDE: Rentals → reduce your FIRE number
───────────────────────────────────────────────
█████████████████ FOUNDATION █████████████████
Spend less than you earn · Automate saving
No high-interest debt
The 10-Step Fill Order
Here's the order I follow and teach. Start at the top and work your way down, but don't wait for one step to fill before starting the next: start each one small and turn it up with every raise.
- Starter emergency fund: $1,000 to one month of expenses in a high-yield savings account. This is your floor, the cushion that keeps one bad week from becoming a financial crisis.
- 401(k) up to the full employer match: Contribute enough to capture every dollar your employer will give you. A dollar-for-dollar match doubles every dollar you put in the day it lands. No investment in history beats free money. If you're not sure what your employer offers, maximizing your employer benefits is worth a few minutes before you pick a percentage.
- Pay off high-interest debt above 7%: Credit cards, personal loans, anything charging you more than what the stock market has returned long-term (about 7% after inflation). Kill it. Every dollar of interest you eliminate is a guaranteed return at that rate. The tradeoff between paying off debt versus investing has more nuance, but 7% is the line I use.
- Full emergency fund (3–6 months of expenses): Now build the real cushion. Three months if you have a stable job and two incomes. Six if your income is variable or you're the sole earner.
- Max the HSA: If you have a high-deductible health plan, fill this next. The triple tax advantage makes it the single most efficient account in the tax code. In 2026, that's $4,400 for an individual or $8,750 for a family.
- ESPP: If your employer offers one, enroll, and handle each purchase the way I do: sell it as it settles and send the money down this list. The discount is a quick, reliable gain.
- Max the 401(k): Push your contributions to the $24,500 limit in 2026. If you can't get there right away, increase by one or two percentage points with every raise.
- Mega backdoor Roth: If your employer's plan allows after-tax contributions with in-plan Roth conversions, this lets you move up to $47,500 more into Roth money in 2026: the $72,000 total limit on what goes into a 401(k), minus your $24,500 and whatever your employer's match adds. Not every plan offers it. Ask HR whether yours allows both pieces of the mega backdoor. If yes, you're in.
- Roth IRA or backdoor Roth: Fund a Roth IRA directly if your income is below the phase-out, or use the backdoor method if it's not. Either way, $7,500 more goes into tax-free growth in 2026.
- Taxable brokerage account: Whatever is left goes here. Low-cost index funds, no age restrictions, and if you hold long enough, you can withdraw at the 0% long-term capital gains rate, up to $98,900 of taxable income for married couples filing jointly in 2026.
Why This Order
The order isn't random. Each step earns or saves you more per dollar, or is easier to keep funding, than the one below it.
I put the HSA before the ESPP because the HSA's triple tax advantage beats the ESPP's purchase discount. Through payroll, every dollar in the HSA saves me 30 to 40% in taxes, plus my employer matches a portion, and that compounds for decades. The ESPP discount is usually 10–15%, but it's taxable when I sell, and I sell immediately. Long-term beats short-term every time.
I put the 401(k) maximum and the mega backdoor Roth before the Roth IRA because they're easier to set up. Log into your employer's portal, set a percentage, and you're done. The mega backdoor is one more checkbox: elect after-tax contributions and automatic Roth conversions.
The backdoor Roth IRA requires opening an account, making a non-deductible contribution, converting it, and filing Form 8606. More steps. The account you actually fund beats the one you mean to fund.
This order is a starting point. No high-deductible plan? Skip the HSA. No ESPP or mega backdoor? Skip those and keep going. If cash is tight, never give up the match. Start the other accounts small and raise them with every raise.
How My Accounts Grew
I didn't build all five pillars at once. It took twelve years.
My 401(k) came first, in 2011, and reached the maximum in 2020.
I started backdoor Roth IRA contributions in 2018 after discovering my income was too high for direct contributions. I opened an HSA with a high-deductible health plan in 2020, and since 2021 my wife and I have filled the IRS family limit every year across our two HSAs. I added the mega backdoor Roth in 2023 once my employer's plan allowed it.
None of these happened on January 1st of a year, going from zero to full. Each one was a gradual progression. I started small, tried it, learned how it worked, and turned it up as my income and confidence grew. The years are when each account started or reached the maximum, not switches I flipped. That's why I call them experiments.
For years, the tax-advantaged boxes came first, ahead of most of my taxable investing, in the order above. In those years, our tax-advantaged contributions were a substantial share of our pay. I tracked it all in my net worth tracker, watching each pillar grow quarter by quarter.
The Coast FIRE Exception
The fill order has one big exception: early retirement.
I maxed my 401(k) for years. For a stretch my wife maxed her 403(b) too, and together they became the largest single piece of how we got there. Now I contribute only enough to get the full employer match.
The switch wasn't abrupt. After reaching Coast FIRE in 2024, I wound down the mega backdoor step by step until it stopped in 2025. My retirement accounts can grow to what I need by traditional retirement age without more money from me, thanks to compound interest doing the heavy lifting.
What I need now is money I can reach before 59½, because most 401(k) withdrawals before then carry a 10% penalty. So these days, past the match, the brokerage account gets the bulk of what I invest, in the same low-cost index funds, with no age rules for when I can use it. I give up some tax deferral for flexibility. Stopping at the match only works when the rest goes somewhere on purpose.
If your retirement accounts are already on track to reach your number at 7% a year, make the same shift. If you plan to work into your 60s, maxing the 401(k) is hard to beat.
Planning the Order as a Couple
I have a 401(k), my wife has a 403(b), and we both have an HSA. Planning FIRE as a couple means we treat our accounts as one household. Both partners contributing to a workplace plan doubles the tax-advantaged room a single person gets. If your household covers expenses on one income, a second income can go almost entirely toward investments.
The mix of Roth and traditional money across both of our accounts is one household plan. We split HSA contributions between our paychecks to capture both employer matches and max out the family limit. When we first started optimizing together, I got obsessed with comparing fund options and running scenarios on Roth versus traditional contributions. My wife finally pulled me back to reality: “We can optimize forever, or we can just max out both accounts and move on with our lives.” She was right.
Write Down Your Fill Order
This isn't a rigid rule. It's a starting framework any beginner can follow. The alternative is figuring it out the way I did: one account at a time, one mistake at a time. Start early and tweak the order as your income, your job, or your goals change.
Write down your fill order so every dollar goes somewhere on purpose.
If you have kids, the next question is where their money should go, after every pillar above: kids' accounts.
What You Need to Remember
- Your five pillars (cash, 401(k), HSA, Roth, and taxable brokerage) each serve a distinct role, and removing any one weakens your plan.
- Follow the 10-step fill order so every dollar goes where it does the most: a starter cushion and the match first, then high-interest debt and the full emergency fund, then the tax-advantaged accounts, then taxable.
- Start each pillar small and increase contributions gradually with every raise rather than trying to max everything at once.
- Once your retirement accounts can reach your FIRE number growing at 7% a year with no new contributions, shift new dollars to a taxable brokerage you can access before 59½.
- Write down your fill order, automate it, and revisit it when your income, job, or goals change.
Questions I Always Get
What if I can't afford to fund all ten steps? You don't have to fund all ten at once. I didn't for twelve years. Never skip the employer match, because no other step hands you free money. After that, start small on whatever step you're at and increase by a percentage point with every raise. The order matters more than the amount you put in at any given step.
Should I prioritize paying off my mortgage before investing? If your mortgage rate is below 7%, keep paying the minimum and invest the difference. Mortgage debt is usually low-interest, and its interest is deductible if you itemize, so it rarely qualifies as the high-interest debt the fill order targets in Step 3. If your rate is above 7%, treat it the same as credit card debt and prioritize paying it down.
How do I know when I've reached Coast FIRE and can stop maxing my 401(k)? Calculate whether your current retirement balance, growing at about 7% annually with no new contributions, will reach your FIRE number by traditional retirement age. If it does, you've hit Coast FIRE. At that point, if you plan to stop working before 59½, drop your 401(k) to the match and redirect every extra dollar into a taxable brokerage account you can reach before then.
Can I swap the HSA and ESPP steps? Keep the HSA first. Its tax savings, plus any employer contribution, beat a 15% ESPP discount, and the triple tax advantage compounds for decades. The one exception is tight cash: then funding the ESPP first for a while and selling each purchase right away gives you a quick gain to reinvest.
What if my employer doesn't offer a mega backdoor Roth or ESPP? Skip those steps and keep moving down the list. The fill order is a framework, not a rigid checklist: only steps available to you apply. Without an ESPP or mega backdoor, you'd go from maxing your 401(k) directly to funding a Roth IRA or backdoor Roth, then to your taxable brokerage account. The order still works with fewer steps.