Executive Summary: Taxes matter—but not in the way most investors think. The goal isn’t to minimize your tax bill; it’s to maximize what you keep after taxes. In this report, I break down how taxes affect Vanguard fund returns, show which funds hold up best after the IRS takes its cut, and explain why focusing on tax efficiency alone can lead you astray.
Paying taxes is a good thing—it means you’ve made money.
But from an investment standpoint, taxes are still a cost. And like any cost, they should be managed, not avoided at all costs.
That distinction matters more than most investors realize.
Too often, investors fixate on minimizing their tax bill instead of maximizing what they keep. Why? Because taxes are visible—and painful. You get a bill every year.
After-tax returns, on the other hand, are easy to ignore. They’re rarely shown, rarely discussed and quietly chipped away over time.
So, as I do each year, I’m going to bring those after-tax returns out of the shadows.
We’ll start with the basics, then look at how Vanguard’s funds stack up. That will set the stage for a future article tackling the question I hear most often: “Can I follow your Model Portfolios in a taxable account?”
Key Takeaways
- The goal isn’t to minimize taxes—it’s to maximize after-tax returns.
- A tax-efficient fund with mediocre returns won’t beat a higher-return fund, even after taxes.
- Index funds tend to be more tax-efficient—but not always better after taxes.
Additional Reading
Tax efficiency is a deep topic—and if you want to go further, these pieces will help:
- ETFs Basics: 101 and 102
- Why Vanguard’s index-based ETFs don’t have a tax edge over its index mutual funds.
- Are Vanguard’s actively managed ETFs as tax-friendly as their mutual fund siblings?
- Do active managers outperform after taxes?
- Municipal bonds as an alternative to asset location strategies.
- How ETFs and index mutual funds let you decide when to pay taxes.
Which After-Tax Returns?
The mutual fund and ETF performance you see quoted pretty much everywhere, including our Performance Review tables, is calculated without regard for taxes.
That’s generally the right way to look at returns. Many investors hold funds in tax-deferred accounts, where taxes aren’t an issue. And even in taxable accounts, each investor’s situation is unique—your tax bill won’t match mine.
But taxes aren’t something we can ignore entirely.
Even if you never sell a fund and therefore don’t trigger a capital gain, mutual funds and ETFs still make annual distributions. Those payouts—dividends, interest and capital gains—are taxable. As a result, a portion of your return is quietly siphoned off each year.
That’s why it’s worth taking a closer look at after-tax returns.
There are two ways to measure after-tax returns:
- Returns after taxes (distributions only): Adjusts for the taxes you pay each year on dividends, interest and capital gains distributions.
- Returns after taxes (distributions and sale): Adds the tax bill you’d face if you sold your shares.
I see the merits of both methods. But to keep things simple for long-term investors like us who aren’t selling shares every year, I focus on the first measure. So, throughout this report, “after-tax returns” refers to returns after taxes on distributions, assuming you continue to hold your shares.
For this analysis, I applied a 20% tax rate to qualified dividends and long-term capital gains and a 43.4% rate to interest income and short-term gains. (To keep things simple, I’ve excluded state and local taxes.) All figures are as of March 31, 2026.
Once we have before- and after-tax returns, we can calculate a fund’s tax efficiency—the percentage of its return that investors actually keep.
That concept sounds abstract, so let’s make it concrete.
Windsor (VWNDX) earned an 11.3% annualized return over the past decade. After taxes, investors in taxable accounts kept just 9.1%—a tax efficiency of 80%. In other words, taxes consumed one-fifth of the fund’s returns, whether you noticed it or not.
You might wonder why funds distribute income at all, effectively handing shareholders a tax bill.
In short: They have no choice.
By law, mutual funds and ETFs must distribute the income they receive—interest and dividends—at least once a year. They must also pass along any net capital gains generated by trading activity. And remember, every fund trades, even index funds.
How much tax you pay isn’t just about what a fund earns. Structure plays a role, too—and this is where ETFs often enter the conversation.
Mutual funds and ETFs are on equal footing when it comes to dividends and interest. But ETFs generally have an edge in managing capital gains, thanks to their structure. (I explain how that works here.) However—as I’ve said before—Vanguard’s index mutual funds and ETFs are simply different share classes of the same underlying portfolios, so they receive identical tax treatment.
Still, broadly speaking, this difference in tax treatment goes a long way to explaining why active managers are embracing the ETF structure after years of resisting it.
The Number That Counts: What You Keep After Taxes
Definitions are helpful, but what really matters is how this plays out in real portfolios. The goal isn’t to avoid taxes—it’s to maximize what you keep after paying them.
So, let’s look at the data.
I’ve packed a lot of data into these tables—more than is easy to digest on a screen. If you plan to spend time with them, the PDF is your friend.