I recently got remarried and went to change my 401K beneficiary form. Because I have a substantial amount of money in this account I want to split my beneficiary to a split between my new wife and my two children. The form that my company supplied me indicates that I can not designate a new primary beneficiary other than my wife unless she gives written consent. This seems like it can not be right since I acquired these assets prior to marriage. If this is the case what law supports this requirement.

If you have been married to your new wife for more than 1 year I believe she does have to consent to any beneficiary other than herself.

The law behind this rule is ERISA. The rules are set up to protect your spouse. With her consent you can change the beneficiary designation as you suggest.

Please note the same is true for any qualified plans in which she has an account.

i belive if you are naming your spouse as a beneficiary of at least 50% then she does not have to sign a waiver accouding to ERISA(accourding to ERISA spouse are entitled to at least 50% of survivor benefits. I never heard of any time limit.

The plan document controls, regardless of the other possibilities and refinements the law may allow. Expect your plan document to require the spouse to be the beneficiary for all of the account unless the spouse consents to another benefiticiary. Ease of administration of the plan usually dictates these terms. But check it out if you are offended by the idea.