It can be quite concerning to discover that your 401(k) appears to be missing funds. There are a few reasons why your 401(k) account might not show the balance you expected:

1. Forced Rollover to an IRA: If your account balance was $5,000 or less, your former employer's plan might have initiated a forced rollover into a Safe Harbor IRA, in accordance with plan policies. This is often done to manage the cost and complexity of maintaining small accounts. You should check with your plan administrator or review any past statements you have for a record of this transfer.

2. Depletion Due to Fees: 401(k) plans typically come with management and administrative fees. If you had a relatively small balance and left it in the plan after leaving your job, these fees may have increased, particularly if your former employer was subsidizing some of these costs while you were an active employee. Over time, these fees could reduce your balance significantly, potentially to zero. Reviewing your historical statements should help you see if fees have been eating into your balance.

3. Lack of Contributions: If you were enrolled in a 401(k) plan—either by choice or automatically—but never actually set up contributions from your paycheck, your account would not have funds. Your 401(k) provider can confirm whether any deposits were ever made into your account.

If you're facing a zero balance, the best starting points for investigation are:

1. Historical Statements: Obtain and review your past 401(k) statements, which should be accessible through your provider’s website. These documents can offer insights into any rollovers, fees, or lack of contributions that might explain the situation.

2. Direct Contact: Reach out to your 401(k) provider. They can provide specific details about your account's status and history, helping you understand what happened to your funds.

It's crucial to act promptly if you suspect your 401(k) funds are unaccounted for, as there could be other explanations that need addressing.