Yes, you can use your 401k to invest in stocks, and there are two ways it typically happens. Most plans give you stock exposure through mutual funds and index funds chosen by your plan administrator. Roughly 20 to 40 percent of plans go further and offer a self-directed brokerage window that lets you buy shares of individual companies directly.1Department of Labor. Understanding Brokerage Windows in Self-Directed Retirement Plans Whichever path your plan allows, every dollar grows tax-deferred: you owe no capital gains tax when you buy or sell inside the account, and you pay ordinary income tax only when you withdraw the money in retirement.
Stocks Through Your Plan’s Fund Menu
The majority of 401k participants own stocks indirectly, through equity mutual funds or index funds on the plan’s investment menu. A single fund purchase spreads your money across dozens or hundreds of companies. Typical menus include a large-company index fund, an international stock fund, and a target-date fund that gradually shifts from stocks to bonds as you approach retirement.
The cost of these funds matters more than most participants realize. Each fund charges an annual expense ratio, a percentage skimmed from the fund’s assets to cover management. A Department of Labor analysis found equity fund expense ratios in 401k plans ranging from around 0.18% for a basic index fund to over 2% for actively managed funds.2Department of Labor. A Look at 401(k) Plan Fees The average expense ratio 401k participants actually paid on equity mutual funds was 0.26% as of 2024.3Investment Company Institute. Mutual Fund Expense Ratios Remain at Historic Lows for Retirement Savers Over a 30-year career, even a fraction of a percentage point in extra fees can reduce your ending balance by tens of thousands of dollars. Comparing expense ratios across the funds available to you is worth the time.
Buying Individual Stocks: The Self-Directed Brokerage Window
To buy shares of a specific company rather than a fund that holds it, you need a feature called a self-directed brokerage account, sometimes called a brokerage window. This feature expands your options beyond the plan’s preset funds to include individual stocks, ETFs, and often bonds and additional mutual funds.
Not every plan offers it. To find out whether yours does, check your Summary Plan Description, the document that spells out your plan’s rules and investment options.4U.S. Department of Labor. FAQs About Retirement Plans and ERISA You can usually pull it from your plan’s online portal or request it from human resources. The SPD will also list any restrictions on what you can hold and how much of your balance you can move into the brokerage side.
One thing to understand before you go this route: when you pick individual stocks through a brokerage window, you carry the investment risk yourself. Under ERISA Section 404(c), a plan fiduciary is generally shielded from liability for losses that result from your own choices.1Department of Labor. Understanding Brokerage Windows in Self-Directed Retirement Plans If a stock you picked drops in value, there is no backstop. The loss is yours.
Opening and Funding the Brokerage Window
Once you confirm the window is available, you complete election forms to open the brokerage account and link it to your existing 401k balance. The forms typically ask for your plan ID and employment verification. You then specify how much of your core balance, either a dollar amount or a percentage, to move into the brokerage side.
Plans set rules around these transfers. Minimum initial transfers vary by provider; some require as little as $500 to open the brokerage account. Many plans also cap how much of your total balance can sit in the window, with 50% and 95% being common limits.1Department of Labor. Understanding Brokerage Windows in Self-Directed Retirement Plans A smaller number require a minimum balance to remain in the core funds at all times. After you submit the paperwork, the transfer usually appears in the brokerage account within a few business days.
Placing a Trade
With the window funded, you log into the brokerage platform your plan’s custodian provides. The interface works much like any online brokerage. You enter the ticker, choose an order type such as a market order or a limit order, and confirm the trade. Most major providers charge no commission for online stock and ETF trades, though broker-assisted trades and specialized transactions like options may carry fees.1Department of Labor. Understanding Brokerage Windows in Self-Directed Retirement Plans
The individual stocks you buy show up as separate holdings within the brokerage portion of your 401k, but they remain part of your overall balance for tax and reporting purposes. They will appear on your quarterly plan statement alongside your fund holdings.
What You Cannot Buy or Do
A 401k brokerage window is not a regular brokerage account. Several strategies and investment types are off-limits or heavily restricted:
- Margin trading and short selling. Both involve borrowing, and a retirement plan account generally cannot take on debt obligations, so nearly all plans prohibit them.
- Employer stock. Many plans restrict or block purchases of your own employer’s stock through the window, separate from any employer stock fund on the plan menu.
- Collectibles. The tax code treats a purchase of collectibles (artwork, rugs, antiques, most coins, gems, stamps, alcoholic beverages) through an individually directed retirement account as an immediate taxable distribution equal to the purchase price. Certain government-minted gold and silver coins and approved bullion held by a qualified trustee are the exceptions.5Internal Revenue Service. Investments in Collectibles in Individually Directed Qualified Plan Accounts
- Penny stocks and municipal bonds. Plans commonly block these, partly because municipal bond tax benefits are wasted inside a tax-deferred account.
Federal law also bars certain dealings between your 401k and anyone the IRS considers a “disqualified person,” which includes you, your family, and your employer. Prohibited transactions include selling property to your plan, borrowing from it outside an approved loan program, or using plan assets for personal benefit, such as buying artwork through the account and hanging it in your home.6Internal Revenue Service. Retirement Topics – Prohibited Transactions The penalties are steep: a 15% excise tax on the amount involved each year the transaction is uncorrected, and a second-tier 100% tax if it still is not corrected within the required period.7Office of the Law Revision Counsel. 26 U.S.C. 4975 – Tax on Prohibited Transactions
How Taxes Work on 401k Stock Investing
One of the biggest advantages of buying stocks inside a 401k is that individual trades do not trigger taxable events. You can sell a stock at a gain and reinvest the entire proceeds without owing capital gains tax that year. The 401k wrapper, not the type of investment, provides this benefit, and it applies equally to mutual funds and individual stocks.8Office of the Law Revision Counsel. 26 U.S.C. 401 – Qualified Pension, Profit-Sharing, and Stock Bonus Plans
The tax bill arrives when you take money out. Withdrawals from a traditional 401k are taxed as ordinary income, not at the lower long-term capital gains rates, regardless of whether the money came from stock gains, dividends, or your original contributions. For 2026, federal ordinary income tax rates range from 10% to 37% depending on your total taxable income.9Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 Most states also tax retirement distributions.
The Early Withdrawal Penalty
If you pull money out before age 59½, you generally owe an extra 10% tax on top of the regular income tax, whether the money was in mutual funds or individual stocks.10Office of the Law Revision Counsel. 26 U.S.C. 72 – Annuities; Certain Proceeds of Endowment and Life Insurance Contracts Several exceptions can waive the 10%, including leaving your employer during or after the year you turn 55, total and permanent disability, a series of substantially equal periodic payments, distributions to a former spouse under a qualified domestic relations order, and unreimbursed medical expenses over 7.5% of your adjusted gross income. The IRS maintains the full list.11Internal Revenue Service. Retirement Topics – Exceptions to Tax on Early Distributions Even when an exception applies, regular income tax still comes out; only the additional 10% is waived.
How Much You Can Put In for 2026
How much you can invest in stocks through your 401k depends on how much you can contribute in the first place. For 2026, the IRS sets the elective deferral limit at $24,500 from your own paycheck. Employer matching dollars do not count against that limit.12Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500
Older workers can add catch-up contributions. Participants age 50 and older can put in an extra $8,000, for an employee total of $32,500. Participants aged 60 through 63 get a higher catch-up of $11,250 under the SECURE 2.0 Act, for a total of $35,750. These limits apply to your combined contributions across the plan, whether the money lands in core funds or in individual stocks through a brokerage window.12Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500
What Happens to Your Stock Holdings if You Leave
When you leave an employer, your 401k, including any brokerage window holdings, stays in the plan until you decide what to do with it. Many plans, however, require departing employees to close the brokerage window within a set period. That usually means selling your individual stock positions and moving the proceeds back into the core funds or rolling them out of the plan. Some plans allow an in-kind rollover of individual stocks into an IRA, letting you transfer the actual shares without selling, but this depends on both the sending plan’s rules and the receiving IRA custodian’s capabilities.
If you do nothing, the plan may liquidate your brokerage holdings and either move the cash into a default fund or, for small balances, issue a distribution. A distribution triggers ordinary income tax, and if you are under 59½, potentially the 10% penalty as well. Contact your plan administrator before your last day to understand your timeline and your options for rolling the account into an IRA or a new employer’s plan.