A little while back, I wrote about the HSA Shoebox Strategy — the idea that you pay your medical bills out of pocket, save every receipt, let your HSA grow invested in the market, and then reimburse yourself tax-free years later. That post has gotten a lot of traction, which tells me two things: people find it useful, and they probably have a lot of follow-up questions.

So, consider this part two. Not a repeat, but a deeper look at turning your medical bills into longterm wealth.

HSA Triple Tax Advantage

Before we go deeper, it's worth exploring why this matters so much. The HSA is the only account in the tax code that offers a genuine triple tax advantage. Contributions go in pre-tax, growth is tax-deferred, and withdrawals for qualified expenses are tax-free. That's a hat trick the IRS almost never allows.

For high earners, this is especially powerful. If you're in the 37% federal bracket, a dollar contributed to your HSA is worth 37 cents more than a dollar you put anywhere else that doesn't get a deduction. When that same dollar comes out tax-free decades later to cover a medical expense, you've completely eliminated the IRS from that transaction. Not reduced. Eliminated.

By paying for medical expenses out of pocket today and letting the HSA stay invested, you are effectively creating a tax-free emergency fund that you can tap into whenever you want — even twenty years from now.

HSA Qualified Medical Expenses: More Than Just Aspirin

One pitfall I often see is a narrow view of what constitutes qualified medical expenses that owners can track. If you’re only saving receipts for the big stuff — ER visits and surgeries — you’re leaving money on the table.

To maximize the shoebox, you need to think broadly. We aren’t just talking about co-pays. We’re talking about dental work, vision care (hello designer frames with your Rx), chiropractic care, and even certain over-the-counter items that were added back to the list in recent years.

The strategy hinges on the fact that there is currently no expiration date on when you must reimburse yourself. You can incur a charge in 2024 and wait until 2044 to cut yourself a check from the HSA. In the meantime, that $1,000 you didn't withdraw has two decades to potentially grow into $4,000 or $5,000 through the power of compounding.

But the entire strategy hinges on one thing: documentation. You can only reimburse yourself for qualified medical expenses if you have the documentation to prove the expense.

My Personal Shoebox

I practice what I preach, though I’ll admit my "shoebox" is a bit more digital these days. A few years back, my wife and I decided to lock in a High Deductible Health Plan (HDHP) to maximize our HSA contributions.

Naturally, the universe has a sense of humor.

One month after locking in that high-deductible plan, we found out we were expecting our daughter. If you’ve ever looked at a New York City hospital bill for a delivery, you know it isn't exactly "budget-friendly." Between the prenatal care and the delivery, we quickly racked up over $10,000 in medical bills.

The "normal" reaction would be to use the HSA funds to pay those bills immediately. That’s what the money is there for, right? But we chose the trade-off. We decided to pay that $10k+ out of our cash flow (post-tax savings) and leave the HSA untouched.

The Tracking System

To make this work without turning into a disorganized mess, I developed a simple but rigid workflow.

• The Excel Spreadsheet: I keep it simple. Columns for: service date, service amount, service name/provider, commentary (to remind myself what that was for), and status (pending or completed).
• The Digital Folder: Every time a receipt and EOB (explanation of benefits) come in, I snap a photo on my phone and drop it into a dedicated folder.
• The Match: After taking a snapshot, I fill in the Excel with the necessary information, knowing I will likely forget what the expense was months later if I don't do it right away.

That $10,000 delivery bill is still sitting in my “Pending” column. It stayed invested during one of the strongest market runs in history. Now, it has been working for us, tax-free, for years.

The HSA Investment Strategy for the High-Net-Worth

When your income is high, taxes and inflation do more damage to your wealth than any medical bill ever will. That's why your HSA strategy needs to shift from "savings" to "growth." Most people treat an HSA like a secondary checking account. They keep it in cash. That is a mistake. For my clients, I recommend keeping only the minimum required cash balance (usually $1,000-$2,000) and investing every other penny in a diversified portfolio of low-cost index funds or ETFs.

The “Shadow Roth”

Think of your HSA as a "Shadow Roth IRA." If you reach age 65 and you’ve stayed so healthy that you don't have enough receipts to claim all your funds, the HSA simply turns into a traditional IRA. You can withdraw the money for any reason and just pay income tax. But if you do have medical expenses (which we all will in retirement), it’s better than a Roth because the money went in tax-free, too.

In fact, the IRS also mentions that you can use certain Medicare expenses as part of the qualified expenses (but double check your situation as there are some nuances to it). But this really broadens your base of expensible receipts should you be incredibly lucky and have low healthcare costs during your working years.

The Trade-Off

The trade-off here is liquidity. By using the Shoebox Method, you are choosing to feel the "pinch" of paying for medical bills out of your take-home pay today. For someone earning high six to seven figures in income, this is usually a manageable trade-off. You’re trading a small amount of current liquidity for a massive amount of future, tax-free flexibility.

Avoiding the “Lost Receipt” Pitfall

The biggest risk to this strategy is the IRS. If you get audited many years from now and claim a $15,000 tax-free withdrawal, you’d better be able to produce the digital breadcrumbs.

1. Back it up: One cloud folder isn’t enough. Consider using the “Rule of Three”: one on your computer, one in the cloud (Google Drive/Dropbox), and one physical or secondary digital backup.
2. Legibility matters: Thermal receipts (the ones from the pharmacy) fade over time. A photo taken immediately is your best defense against a blank piece of paper in five years.
3. The “Beneficiary Folder”: Make sure your spouse or your executor knows how to access your shoebox records. If your spouse is the designated beneficiary, the account will be treated as your spouse’s HSA after your death. If your spouse isn’t the designated beneficiary, the account stops being an HSA, and the fair market value of the HSA becomes taxable to the beneficiary in the year in which you die. This is why, ultimately, you want to use your account. If you’re in your 70s, now is the time to start taking those withdrawals.

The Long Game

The shoebox strategy isn’t complicated. Like most things in financial planning, the gap between understanding it and executing it year after year is where people either build wealth or let opportunity pass them by.

There are quite a few nuanced rules to this strategy that are not covered in this article.

At Servet Wealth Management, we help professionals in NYC build comprehensive financial plans that don’t leave money on the table. To see if we can help you maximize your tax advantaged accounts and build a strategy that fits your life, schedule a conversation with us today.

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