In my husband's divorce decree it states that his daughter, age 5, from the previous marriage, is sole beneficiary to all his retirement and life insurance policies until the age of 18. We have a child together, and I want to make sure she is taken care of as well. If his ex wife does not agree to the modification of changing beneficiaries, is there anything else that can be done?
You might need an attorney to review his decree. I assume it meant all current life insurance policies at the time of the divorce. I don't see why he can't buy new policies listing you and/or her as new beneficiaries. If he agreed to the retirement benefits, I don't think there is anything you can do about that. He is stuck with what he agreed to in his divorce. I assume that he never anticipated re-marrying or having other children at the time he divorced.
The problem is that the first child is his first priority until she is 18. You knew she existed when you married him. Both you and he knew she existed and this divorce decree existed before you chose to have a child. Unfortunately, your child will be "second banana" until his eldest child turn 18. It might sound cruel but your husband voluntarily signed his Divorce Decree and the court's jurisdiction has ended in terms of modifying the decree. If your husband violates the terms of the decree then he can be held in contempt of court. You can read the decree regarding what can happen if he violates the decree - fines and/or jail plus her attorney's fees and court costs.