How to review your 401(k) with AI

Last updated August 2026

Short answer

A 401(k) review is mostly a reading exercise, and the documents are the annual fee disclosure, the fund menu and the summary plan description. Give those to an assistant and ask three things: does my contribution capture the full match, what is the cheapest sensible fund on this menu, and what am I actually holding. That covers nearly all the money available in a workplace plan.

For most people the 401(k) is the largest account they own and the one they have looked at least, usually because the documents are dull rather than difficult.

Gather three documents

The participant fee disclosure, provided annually, listing fund expense ratios and any plan administrative charge.

The fund menu with the full list of investment options.

The summary plan description, which states the match formula, the vesting schedule and the rules on loans and withdrawals.

Start with the match

Ask what the formula is and what contribution rate captures all of it.

Ask whether the plan offers a true-up, which determines whether front-loading contributions costs you match on later pay periods.

This is the highest-return question available anywhere in personal finance, and it takes one exchange to answer.

Then the costs

Ask for every fund on the menu with its expense ratio, sorted by cost, alongside the index or strategy each one follows.

Compare what you hold against the cheapest broad option, since two funds tracking similar indexes can differ substantially in price.

Add any plan-level administrative fee, because it applies on top and is deducted rather than billed.

Try it in Walnut

Walnut connects to brokerage accounts and analyses what you hold. Whether a workplace plan can be connected depends on the recordkeeper.

Then what you are actually holding

Ask what the current allocation is and what the target-date fund's glide path implies at the year on its label.

Combine it with your other accounts, because a conservative fund at work alongside concentrated equity elsewhere is one portfolio and neither description fits it.

Ask where the overlap sits, since a plan fund and a retail fund you own separately can hold the same companies.

Questions people forget

The vesting schedule, which decides how much of the employer contribution is yours if you leave.

Whether the plan offers a Roth option and after-tax contributions, the second of which enables a mega backdoor arrangement in some plans.

Whether the plan accepts incoming rollovers, which is the route for clearing pre-tax IRA balances before a backdoor Roth.

What not to expect

A live connection, since most recordkeepers do not offer one to outside tools.

A judgment about how much to contribute, which is a budget decision rather than an analytical one.

Certainty about the numbers, which should be checked against the disclosure rather than accepted, exactly as with any other document-based answer.

The annual version of this

Twenty minutes, once a year, on three documents that arrive whether or not anybody reads them.

Confirm the match, compare the cost of what you hold against the cheapest broad option, and check the allocation across every account together.

Then leave it alone, because a workplace plan rewards attention once a year and punishes it monthly.

Sources

Plan disclosures and participant rights are described by the Department of Labor at Types of Retirement Plans, with contribution limits for 2026 in IRS Notice 2025-67. Walnut is informational and is not an investment adviser. This guide is educational and not personalized investment advice.

FAQ

What can AI actually do with my 401(k)?

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Read the documents. The fee disclosure, the fund menu and the summary plan description are text, and most of the money in a workplace plan is decided by things stated in them that participants never read.

Can it connect to my plan?

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Frequently not. Workplace plans are administered by recordkeepers that often do not connect to outside tools, so the practical approach is uploading or pasting the documents rather than expecting a live link.

What should I ask first?

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What the match formula is and whether my current contribution captures all of it. That is the highest-value question in any workplace plan and it has a definite answer in the plan documents.

How do I compare the fund menu?

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Ask for every option with its expense ratio, sorted by cost, with the index each one tracks. That single table usually reveals a cheaper equivalent to whatever the plan defaulted you into.

What about the target-date fund?

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Ask for its expense ratio and its glide path, meaning how much equity it holds at the target year. Two funds with the same year on the label can hold quite different amounts, which matters more than the name suggests.

Can it tell me my overall allocation?

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Only if it can see everything, so combining the workplace plan with your other accounts is the point. A conservative fund at work alongside concentrated equity elsewhere is a single portfolio that is neither.

What about the vesting schedule?

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Worth asking about explicitly, because it determines how much of the employer contribution is actually yours today. It becomes decision-relevant the moment you consider changing jobs.

What should I not delegate?

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The contribution rate, which is a decision about your budget rather than an analysis. Everything on this page helps you spend the same money better; none of it substitutes for putting more in.

How long does a review take?

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About twenty minutes once a year, on three documents that arrive whether or not anybody reads them. Confirm the match, compare what you hold against the cheapest broad option, check the allocation across every account, then leave it alone.

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