Portfolio Construction for Taxable Accounts

Portfolio construction for a taxable brokerage account requires a deliberate allocation of assets across multiple account types to minimize annual tax drag without distorting your target asset allocation. The principle is simple: place tax-inefficient holdings (bonds, REITs, actively traded funds) in tax-advantaged accounts, and hold tax-efficient holdings (low-turnover index funds, individual stocks) in taxable accounts.

The core problem: tax drag on taxable accounts

When you hold investments in a taxable brokerage account, you owe federal (and often state) income tax on:

• Dividends paid by stocks or funds (ordinary income tax rates, typically 15–37%).
• Interest from bonds or money-market funds (ordinary income tax rates).
• Capital gains realized when you sell a position at a profit (long-term gains taxed at 0%, 15%, or 20%; short-term gains taxed as ordinary income).
• Fund distributions from mutual funds that realize gains internally and distribute them to shareholders.

In a 401(k) plan or traditional IRA, these taxes are deferred or eliminated until withdrawal (or forever, in a Roth IRA). In a taxable account, you owe tax annually on interest, dividends, and realized gains, even if you reinvest all proceeds. This annual tax drag compounds over decades.

The solution is not to avoid taxable accounts—they provide flexibility and no contribution limits—but to be strategic about which holdings belong in them.

Asset location: matching accounts to asset types

The principle of asset location (different from asset allocation) assigns holdings to account types based on their tax efficiency. Here is the hierarchy:

Tax-inefficient (belong in tax-advantaged accounts):

• Taxable bonds and bond funds—every coupon payment is ordinary income.
• REITs (real estate investment trusts)—required to distribute 90% of income to shareholders as ordinary income.
• Actively managed mutual funds—frequent trading generates realized capital gains.
• High-yield bonds and junk bonds—high coupon = high annual tax.
• Commodities and commodity futures—often taxed unfavorably (Section 1256 contracts).

Tax-efficient (suitable for taxable accounts):

• Index funds (S&P 500 index funds, total market funds)—low turnover, deferred gains.
• ETFs—generally more tax-efficient than mutual funds due to creation/redemption mechanics.
• Individual stocks—you control the timing of sales; can harvest losses strategically.
• Growth stocks—defer taxes by holding; dividends often lower than value stocks.

Tax-neutral:

• Money-market funds and cash—held in any account, though cash in taxable accounts earns taxable interest.

A model allocation across accounts

Suppose you have a $1 million portfolio with a target of 60% stocks / 40% bonds and access to a taxable account, a 401(k), and an IRA.

Result: You achieve 60/40 allocation across all accounts while placing all bonds and REITs in sheltered accounts.

Using new contributions and withdrawals, not sales

The danger of asset location is that rebalancing can trigger capital gains taxes. If you must shift holdings to correct location, you might realize a large gain. The solution is to:

1. Redirect new contributions to the account furthest from target. If your taxable account has too many bonds, direct your next 401(k) contribution to bonds and your next taxable contribution to stocks.

2. Use withdrawals and distributions to rebalance. If you withdraw $10,000 from your 401(k), don’t just reinvest it in bonds. Instead, reinvest bonds, allowing your taxable account to shift toward stocks.

3. Avoid selling appreciated positions in taxable accounts to fund purchases in other accounts. This crystallizes gains unnecessarily.

Over time, rebalancing via contributions and withdrawals keeps asset location optimized without realizing gains.

Tax-loss harvesting in taxable accounts

A taxable account offers a tool unavailable in tax-advantaged accounts: tax-loss harvesting. When a position falls below your cost basis, you can sell it, realizing a loss that offsets other gains or (up to $3,000 per year) ordinary income.

You then immediately repurchase a similar (but not identical, to avoid the wash-sale rule) security. The upshot: you lock in a tax deduction while maintaining your market exposure.

For example, if you hold a US broad-market index fund that has fallen in value, you can sell it and immediately buy a total-market ETF. You capture the loss tax-free while staying invested. Tax-loss harvesting can be worth 0.5–1% annually in a well-managed taxable account.

Revisiting allocation over time

Asset location is not static. Life changes and account balances shift. When your 401(k) accumulates significant wealth (say, $800k) and your taxable account is smaller, you may have “too much” bond exposure in tax-advantaged accounts relative to your target.

A periodic review (every 3–5 years) helps. Ask: Are my assets still in the right accounts relative to my target allocation? If your taxable account has swollen due to contributions and gains, it may now hold too many bonds (which are tax-inefficient). Direct future contributions accordingly.

Similarly, in retirement, you may draw from accounts in a specific order. A retiree might draw from taxable accounts first (deferring required minimum distributions on traditional IRAs) or Roth IRAs last (preserving tax-free growth). Asset location decisions should anticipate your withdrawal strategy.

The impact: quantifying tax drag

The benefit of optimal asset location is substantial for large, long-held portfolios. Studies suggest that tax-naive asset allocation (holding bonds and REITs in taxable accounts) can cost 0.5–2% annually in after-tax returns, depending on:

• Portfolio size: Larger portfolios benefit more (absolute taxes are higher).
• Turnover: Active traders incur larger gains; index investors benefit most.
• Time horizon: Longer holding periods amplify the compounding benefit.
• Tax brackets: Higher earners face higher tax rates on dividends and gains.

For a $500,000 portfolio earning 6% annually, a 1% annual tax drag translates to $3,000 per year in foregone after-tax returns. Over 30 years, that compounds to over $200,000 in lost wealth.

Conversely, disciplined asset location and tax-loss harvesting can recover much of this drag.

See also