Courts have ruled that a prenuptial agreement for qualified plan (including 401(k)) assets is invalid. The logic is that only a spouse can give up the rights to spousal benefits. When someone signs a prenuptial agreement, that person is not considered a spouse at the time of signing. Where couples agree that the spouse will not make any claim to the assets, it is often recommended that :
- A postnuptial agreement be signed immediately after marriage
The spouse sign a beneficiary designation form giving up rights to the assets immediately after marriage.
The document be notarized or witnessed by a plan representative.