There are several ways to find an old 401(k). Note that your 401(k) funds are held by a plan administrator or a custodian, not directly by your employer or previous employer. Here's how to locate it:

1. Check old statements. If you have any old statements from your 401(k) plan, they can be very helpful. These statements should include contact information for the plan administrator or the financial institution that holds your 401(k) funds.

2. Contact the Plan Administrator: If you know who the plan administrator was (e.g., a financial services firm like Fidelity), contact them directly. They should have records of your account and can guide you on how to access your funds.

3. Use Capitalize resources: Capitalize has an employer search and a 401(k) finding service. You can check these resources to find your Plan Administrator which is where your funds should be held.

4. Contact Former Co-workers: Someone who worked in the finance or human resources department might have information on the 401(k) plan or the plan administrator. You can also use resources like LinkedIn to track down the right people.

5. Use the National Registry of Unclaimed Retirement Benefits: This is a database where employers and plan administrators can report unclaimed accounts. You can search for your name to see if any of your previous 401(k) accounts are listed. Visit unclaimedretirementbenefits.com for more information.

6. Use the IRS and Social Security Administration (SSA) resources: The IRS provides guidance on how to find a lost 401(k), including Form 5500 searches, which can reveal the plan administrator. The SSA may also send notices if you have retirement benefits that you haven't claimed.