The Same Investments, Two Different Tax Bills
Most people think asset allocation — how much goes into stocks versus bonds — is the only decision that matters. But two investors with identical portfolios can end up with very different after-tax returns depending on which account holds which asset. That’s asset location, and it’s one of the few truly free upgrades available to anyone with more than one type of account: a 401(k), a Roth IRA, and a regular taxable brokerage account.
Why Account Type Changes the Math
Different investments generate different kinds of taxable income. Bonds and REITs throw off interest and dividends that are taxed every year at ordinary income rates — some of the highest rates you’ll ever pay. Stock index funds, by contrast, mostly generate unrealized gains that aren’t taxed until you sell, and even then often at lower long-term capital gains rates. That difference means the “tax drag” on a bond fund sitting in a taxable account can be two or three times higher than the drag on a stock fund sitting in the same account.
The General Rule of Thumb
Put your most tax-inefficient assets — bonds, REITs, high-turnover active funds — inside tax-sheltered accounts like a 401(k) or traditional IRA, where the annual interest and dividends aren’t taxed until withdrawal. Put your most tax-efficient assets — broad stock index funds you plan to hold for years — in your taxable brokerage account, where they’ll mostly just accumulate unrealized gains. Your Roth IRA, which grows and withdraws completely tax-free, is the best home for whatever you expect to grow the most over decades, since none of that growth will ever be taxed.
A Concrete Example
Say you want a 60/40 stock-bond portfolio split across a $200,000 401(k) and a $100,000 taxable account. Instead of holding 60/40 in both accounts separately, you’d hold all $120,000 of bonds inside the 401(k) (since it’s tax-sheltered anyway) and fill the rest of the 401(k) plus the entire taxable account with stocks. The blended allocation across your whole portfolio is identical — still 60/40 — but the bonds’ annual interest payments are shielded from yearly taxation, while the taxable account only holds assets that barely generate a tax bill until you choose to sell.
What to Actually Do This Week
List every account you hold and what’s in each one. If you see bond funds or REITs sitting in a regular taxable brokerage account while your 401(k) is full of stock funds, that’s backwards from a tax-efficiency standpoint. Rebalancing across accounts to fix this costs nothing and triggers no immediate taxes if done inside the tax-sheltered accounts — only moves within your taxable account can trigger capital gains, so plan those around low-income years or tax-loss harvesting opportunities.
