You need a prenup that states:

• Each party's 401(k) remains their own separate property, regardless of what happens during the marriage.

How to Create a Simple Prenup for 401(k) Protection:

1. Have an Open Discussion:

• You and your partner should agree that:
  • You’re entering the prenup voluntarily.
  • You’re disclosing all current assets (including 401(k) accounts).
  • You want to exclude 401(k) accounts (and their growth) from community/marital property.

2. Clearly List the 401(k) Accounts in the Prenup:

• Identify each account:
• • "All funds currently held in their respective 401(k) retirement accounts, as well as any interest, gains, contributions, rollovers, or other increases to those accounts during the marriage, shall remain the separate property of the original account holder and shall not be subject to division or claim by the other party in the event of divorce, separation, or death."
• You can list the account provider (e.g., Fidelity, Vanguard) and the last known balance for clarity.

3. Other Key Clauses to Include:

• Full Asset Disclosure:
  • Required in most states to ensure enforceability.
• Waiver of Community/Marital Property Claim:
  • Each party waives rights to the other’s 401(k).
• Acknowledgment of Independent Legal Advice:
  • Not legally required everywhere but strongly recommended.

4. Do You Need a Lawyer?

• You can draft it yourself, but for legal enforceability:
  • Signed before the marriage.
  • Both parties have the chance to consult an attorney.
  • No duress or coercion.
  • Full financial disclosure.
• Best Practice:
  • Draft it first, then each party reviews it with their own attorney for stronger enforceability.

Is there a template for something like this?

Yes, here is a prenuptial agreement template you can use for this purpose.