Yes, you can trade stocks in your 401k, but only if your employer’s plan includes a self-directed brokerage window. Most plans limit you to a menu of mutual funds and target-date funds, so the first thing to check is whether your specific plan offers that feature. If it does, buying and selling individual stocks happens inside the same tax-deferred wrapper as the rest of your account: no capital gains tax on profits, no tax on dividends until you withdraw.
Why Most 401k Plans Don’t Let You Pick Stocks
Federal law makes your employer a fiduciary of the plan. Under 29 U.S.C. § 1104(a), that duty includes diversifying investments to minimize the risk of large losses.1Office of the Law Revision Counsel. 29 USC 1104 – Fiduciary Duties To meet it, most sponsors build a curated lineup of 15 to 30 funds and leave individual stocks off entirely. A single stock that later collapses can invite lawsuits from participants, so the limited menu is a risk-management choice rather than a legal ban on stock trading.
The escape valve is 29 U.S.C. § 1104(c), often called ERISA Section 404(c). When a plan lets you direct your own investments, the fiduciary is not liable for losses that result from your choices.2Office of the Law Revision Counsel. 29 USC 1104 – Fiduciary Duties That safe harbor is what makes brokerage windows possible.
How to Tell If Your Plan Offers a Brokerage Window
A self-directed brokerage account (sometimes labeled “brokerage link” or SDBA) is a sub-account inside your 401k that connects to a third-party broker. It gives you access to thousands of individual stocks, ETFs, and other exchange-listed securities instead of the plan’s standard fund list.3Internal Revenue Service. Retirement Topics – Participant-Directed Accounts
Not every plan includes one. A Department of Labor advisory council report found that plans offering the feature often cap how much of your balance can move into it, with 50 percent being the most common ceiling.4U.S. Department of Labor. Understanding Brokerage Windows in Self-Directed Retirement Plans Your plan documents, plan administrator, or the benefits portal will confirm whether the window exists and what limits apply.
Opening and Funding the Sub-Account
If your plan offers the window, enrollment usually involves these steps:
- Request the SDBA acknowledgment form from your plan administrator or plan website. It typically includes a waiver confirming you understand the risks and that your employer is not responsible for your investment results.
- Provide identifying information, including your plan ID and Social Security number, so the brokerage firm can link the sub-account to your existing 401k balance.
- Keep the required minimum in your core 401k account, commonly $1,000 to $2,500, to cover administrative fees before you move money into the window.
- Transfer funds by selling existing fund shares or redirecting future contributions. Mutual fund redemptions typically settle as available cash in one to two business days.
Some plans charge a monthly or quarterly maintenance fee for the brokerage window. These range from nothing to $15 or more per month, so review the fee schedule before enrolling.
Placing a Trade
Once cash settles in the sub-account, trading works much like a retail brokerage account. Enter the ticker, pick an order type (market or limit), specify shares or a dollar amount, and confirm. Most major brokers charge $0 commissions on online stock and ETF trades, though some plans still carry per-trade fees.
U.S. stock trades settle on a T+1 basis, meaning one business day after the trade date.5SEC Office of Investor Education and Advocacy. New T+1 Settlement Cycle – What Investors Need to Know A trade you place on Monday settles Tuesday, and any remaining cash appears in your account the same day.
What You Cannot Trade or Do
Even with a brokerage window, some investments and strategies are off-limits. Under 26 U.S.C. § 408(m), if a participant-directed account in a qualified plan buys a “collectible,” the purchase is treated as an immediate taxable distribution. Collectibles include artwork, rugs, antiques, gems, stamps, most coins (with narrow exceptions for certain U.S. Mint gold and silver coins), and alcoholic beverages, along with any other tangible personal property the IRS designates.6Office of the Law Revision Counsel. 26 USC 408 – Individual Retirement Accounts7Internal Revenue Service. Investments in Collectibles in Individually Directed Qualified Plan Accounts
Brokerage firms and plan rules also typically block several trading strategies inside retirement accounts:
- Margin borrowing. You cannot borrow against your holdings to fund trades. Retirement accounts do not allow full margin.
- Short selling. Betting a stock will fall by selling shares you don’t own requires margin and is not permitted.
- Naked options. Writing uncovered options is prohibited. Some plans allow limited strategies like covered calls or cash-secured puts, but availability varies.
Federal law also bars “prohibited transactions” between a plan and a “disqualified person,” a category that covers the employer, plan fiduciaries, service providers, and certain family members. Under 26 U.S.C. § 4975, you cannot use your 401k to buy from or sell to your employer outside legitimate employer stock programs, lend money to yourself beyond a qualifying plan loan, or otherwise engage in self-dealing.8Office of the Law Revision Counsel. 26 USC 4975 – Tax on Prohibited Transactions
How Trades Are Taxed Inside the Plan
A qualified 401k plan holds assets in a trust that is exempt from federal income tax under 26 U.S.C. § 501(a).9Office of the Law Revision Counsel. 26 USC 401 – Qualified Pension, Profit-Sharing, and Stock Bonus Plans Everything that happens inside the account, including buying and selling stocks and collecting dividends, takes place tax-free. You will not receive a Form 1099-B for sales or a 1099-DIV for dividends earned in the plan, and no capital gains tax is owed no matter how often you trade.
The flip side: because there are no taxable gains, capital losses inside the account have no tax benefit. A losing stock sale in your 401k cannot reduce your outside tax bill.
The Wash Sale Trap
Trades inside the plan can still affect the taxes on your regular brokerage account. Under 26 U.S.C. § 1091, if you sell a security at a loss in a taxable account and buy a “substantially identical” security within 30 days in any account you control, including your 401k, the loss is disallowed.10Office of the Law Revision Counsel. 26 USC 1091 – Loss From Wash Sales of Stock or Securities
The IRS confirmed this in Revenue Ruling 2008-5, and it added that the basis in the retirement account is not increased to compensate for the disallowed loss.11IRS.gov. Revenue Ruling 2008-5 – Loss From Wash Sales of Stock or Securities If you plan to harvest a loss in your taxable account, wait at least 31 days before repurchasing that stock in your 401k brokerage window.
Taxes and Penalties on the Way Out
The tax deferral ends at distribution. Under 26 U.S.C. § 402(a), amounts you take from a qualified 401k trust are taxed as ordinary income in the year received.12Office of the Law Revision Counsel. 26 USC 402 – Taxability of Beneficiary of Employees Trust Stock gains and dividends that grew tax-free in the account come out at your regular income tax rate, not the lower long-term capital gains rate.
If you withdraw before age 59½, the IRS adds a 10 percent early distribution penalty under 26 U.S.C. § 72(t).13Office of the Law Revision Counsel. 26 USC 72 – Annuities, Certain Proceeds of Endowment and Life Insurance Contracts Exceptions cover separation from service at age 55 or older, disability, death, qualified domestic relations orders, and a few other narrow situations. In general, distributions become available at age 59½, on separation from your employer, on disability, or when the plan terminates.14Internal Revenue Service. 401(k) Resource Guide – Plan Participants – General Distribution Rules
If your brokerage window holds individual stocks and you want to take a distribution, you typically sell those positions first and convert to cash, though some plans and IRA rollovers allow in-kind stock transfers.
Required Minimum Distributions
Starting at age 73, or the year you retire if later, you must take required minimum distributions each year. If you fall short, the IRS imposes a 25 percent excise tax on the missed amount, reduced to 10 percent if corrected within two years.15Internal Revenue Service. RMD Comparison Chart – IRAs vs. Defined Contribution Plans If you would rather not sell specific stocks in the brokerage window, you can sell other holdings in the plan to raise the cash, but the total distribution must still meet the RMD, and RMDs cannot be rolled over.14Internal Revenue Service. 401(k) Resource Guide – Plan Participants – General Distribution Rules
Contribution Limits Still Apply
Using the brokerage window does not give you more room to contribute. The same annual limits cover the entire 401k. For 2026, the IRS set the employee elective deferral limit at $24,500. If you are 50 or older, you can add $8,000 in catch-up contributions for a total of $32,500. A higher catch-up of $11,250 applies for ages 60 through 63, bringing the possible employee total to $35,750.16Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500 Employer matching contributions do not count against these limits, but money you route into the brokerage window still comes from the same contribution pool as your fund investments.