Somewhere in your 401(k) menu there may be an option that doesn't look like the others. Not a fund, but a door. Depending on your provider it's called a self-directed brokerage account, a brokerage window, a Personal Choice Retirement Account at Schwab, or BrokerageLink at Fidelity. Click it and you leave the curated list of funds your employer assembled and enter something closer to an ordinary brokerage account, still inside the plan and still tax-advantaged.
Most people who find this option do one of two things. They ignore it, or they use it to buy a few individual stocks they have a feeling about. Both are understandable and both miss what the feature is actually good for.
How common is this, really
Less common than you'd think. According to the Plan Sponsor Council of America, about 26 percent of plans offer a brokerage window, with adoption concentrated among larger employers. So if your plan has one, you're in the minority, and you're probably at a big company.
Among people who do use them, balances skew high. Charles Schwab's SDBA Indicators Report put the average account balance across the participants it tracks at $383,087 in the third quarter of 2025. That number gets quoted a lot, and it gets misread a lot. It is not a typical 401(k) balance and it is not a target. It tells you something narrower and more useful: brokerage windows are mostly used by people who already have substantial balances, which is a hint about when the feature starts to earn its keep.
The thing that actually changes when you step through the door
This is the part worth understanding before you move a dollar.
The funds on your plan's main menu are what federal rules call designated investment alternatives. Your plan's fiduciaries have a legal duty to select them prudently and to keep monitoring them, and that duty is the reason the menu is short. Someone had to defend every option on it.
A brokerage window is not one of those. The Department of Labor's proposed rule on fiduciary duties in selecting designated investment alternatives, published in March 2026, expressly excludes brokerage windows and self-directed brokerage accounts from that definition, which is consistent with how the DOL has treated them for years. The DOL has also published its own explainer on brokerage windows if you want the primary source.
In plain terms: nobody is watching what you pick in there. The core menu comes with a layer of professional oversight you didn't ask for and probably didn't know about. The window doesn't. That's not a warning against using it. It's the actual nature of the trade, and it's the reason the next section matters.
What a window is genuinely useful for
Three situations come up repeatedly.
The first is a real gap in the menu. Plan lineups are built to be defensible, which means they're often complete in the broad strokes and thin in specific places. If your plan has no international small-cap exposure, no inflation-protected bond option, or no low-cost index fund in a category where the only choice is an expensive active fund, a window can fill that hole. That's a structural argument, and it's the strongest one.
The second is coordination across accounts. If you have an IRA, a taxable brokerage account, a spouse's 401(k), and your own plan, the sensible way to think about allocation is across the whole household, not account by account. Sometimes the tax-deferred account is the right home for the asset class that generates the most taxable income, and sometimes your plan's menu doesn't offer that asset class. A window makes the household-level plan executable instead of theoretical.
The third is cost, occasionally. Plan menus sometimes carry an older, more expensive share class of a fund when a cheaper share class of the identical strategy exists. A window can be a route around that, though it's worth comparing total cost including any window fees before assuming it's cheaper.
What it's not for
A brokerage window is a poor vehicle for stock picking with money you need in retirement, and the reason isn't moral. It's that you've removed the oversight layer and the plan's automatic features at the same time. Target date glidepaths, automatic rebalancing, and default allocations generally stop applying to the portion of your balance sitting inside the window. Money that drifts for fifteen years because nobody rebalances it is a common and entirely avoidable outcome.
It's also a poor answer to concentration risk, and sometimes it makes concentration worse. If a meaningful share of your net worth is already tied to your employer through company stock, deferred compensation, or simply your paycheck, buying more of the same sector inside your brokerage window compounds a problem rather than diversifying it.
The mechanics people get surprised by
Windows come with their own rules, set by the plan rather than by law, and they vary. Several things worth confirming in your own plan materials before you commit:
Whether there's a separate fee for the window, and whether it's flat or per trade. Whether the plan caps the percentage of your balance you can move into it, since many do. Whether you have to keep a minimum in the core menu. How money gets moved in and out, and how long it takes. Whether loans or in-service withdrawals treat window assets differently. And what happens at retirement or termination, since distribution mechanics can be less straightforward for window holdings than for core funds.
None of these are dealbreakers. They're just the kind of thing that's easier to learn before you're mid-transaction.
How to tell whether it's worth using
A reasonable filter is three questions. Is there something specific the core menu can't do that you actually need? Do you have a written allocation you're implementing, rather than a list of things you'd like to own? And will you or someone on your behalf review and rebalance it on a schedule?
Three yeses, and a window is a useful tool. If the honest answer to the first question is "not really, I just want more choices," the feature is likely to cost you attention without buying you anything. That's not a failure of discipline. Most people's plan menus are adequate for most people's needs, which is what they were designed for.
Common questions
What is a self-directed brokerage account in a 401(k)?
It's an option inside some employer retirement plans that lets you invest beyond the plan's main fund menu, in something closer to an ordinary brokerage account while keeping the money inside the plan and its tax treatment. Depending on the provider it may be branded as a brokerage window, a Personal Choice Retirement Account, or BrokerageLink. About 26 percent of plans offer one, according to the Plan Sponsor Council of America in 2026, with adoption concentrated among larger employers.
Is a brokerage window monitored by my plan's fiduciaries?
Generally not in the way the core menu is. The funds on your plan's main menu are designated investment alternatives that fiduciaries have a duty to select prudently and monitor on an ongoing basis. The Department of Labor's proposed rule published in March 2026 expressly excludes brokerage windows from that definition. Practically, that means the investments you choose inside a window do not carry the same layer of professional oversight, and the responsibility for what you hold there sits with you.
Does a brokerage window cost extra?
Often yes, and it varies by plan. Some charge a flat annual or quarterly fee for access, some charge per trade, and some do both. Because these are set by the plan rather than by law, the only reliable answer is in your own plan materials and the window provider's fee schedule. It's worth comparing total cost, including any window fee, before assuming a fund inside the window is cheaper than a comparable option on the core menu.
Will my target date fund still rebalance money I move into the window?
No. The plan's automatic features, including target date glidepaths, automatic rebalancing, and default allocations, generally stop applying to the portion of your balance held inside the window. Anything in there needs to be reviewed and rebalanced deliberately, either by you or by someone doing it on your behalf. Money left unrebalanced for years is one of the more common problems with these accounts.
How much of my 401(k) can I move into a brokerage window?
That depends on your plan. Many plans cap the percentage of a balance that can be moved into the window and some require a minimum to stay in the core menu. Since this is a plan-level rule rather than a federal one, your summary plan description or the window's enrollment materials are the place to confirm the limit that applies to you.
If you have a window and have never built a strategy around it, that's a reasonable thing to talk through in a complimentary conversation. If what you actually want to know is what your plan is costing you, start with the 401(k) Fee Review. And if you work at SDG&E, where the window is the Personal Choice Retirement Account, the SDG&E retirement planning page covers it alongside the pension and savings plan.
Figures cited above are current as of 2026. Product names are referenced for identification only and do not imply any relationship with or endorsement by the firms named. BAS Financial is not affiliated with, endorsed by, or sponsored by any employer, plan, or provider mentioned. This material is provided for educational and informational purposes only and should not be construed as investment, tax, legal, or retirement planning advice. Participation in a self-directed brokerage account or brokerage window may not be appropriate for all investors. Investment options available through a brokerage window are generally not selected, monitored, or reviewed by plan fiduciaries and may involve additional risks and responsibilities. Individuals are responsible for their own investment decisions and should carefully consider their objectives, risk tolerance, fees, expenses, and overall financial circumstances before investing. Asset allocation and diversification do not guarantee a profit or protect against loss in declining markets.