If my spouse waives his right to my 401k plan, is there any circumstance that the court will still award him my 401k?

Frankly, nothing should surprise you in divorce. Few, if any, divorce laws are absolute. Few, if any decrees of divorce, are 100% reliable and enforceable in every respect. So is there a way to have the court award your ex a share of your 401k plan if he previously waived any rights in your divorce action? Well, assuming that you didn't procure his waiver by fraud or representation or under duress or undue influence or things like these, odds are you're safe. But if you want to know on what basis a decree of divorce can be modified, here's a summary of the applicable case law: To succeed on a petition to modify a divorce decree, the moving party must first show that a substantial material change of circumstances has occurred since the entry of the decree and not contemplated in the decree itself.

Any waiver may be overruled by a Judge. A waiver would be final and set in stone thirty-one days after the Final Judgment is signed by the Judge.

In a divorce, yes. The Court has that power and discretion generally unless there was a proper and enforce agreement to that effect under the law. See an attorney for counsel and guidance.

As long as both of you are in agreement, there should be no reason for the court not to do what you both agree to.