What are my chances of terminating my ex husbands parental rights for a child that is not biologically his?

What does the divorce decree say about the child? If it says something, it is probably what is called "res judicata" and can't be changed.

In the context of your divorce action, you should have established paternity. If you had done that, instead of your ex-husband, you would now be dealing the biological father. Since your ex-husband is the legal father, there is little you can do to terminate his rights without also involving the biological father. However, it is possible that your husband could adopt through the step-parent adoption process provided both your ex-husband and biological father agree.

Based on your statements here, you seem to be more concerned about him saying bad things about you than the effect your plans will have on your child. You cannot turn your child's whole world upside down by taking away the only person they know as dad from them because you are ticked. You will come across very poorly to the judge, and it is likely that the judge will find your attempt too late and against the time limit of two years. Figure out a way to resolve this peacefully and get back to what you used to have. Try to put yourself in his position and how you would feel if he made plans with his new wife and leave you behind.

You need to see an attorney, it is possible, if the circumstances are right, to have an order entered that he is not the father (and therefore has no paternal rights). This is fact driven and without details there is no means by which to predict the result of such an action.

In partial answer to your inquiry, it all depends on the actual facts of your case. The first thing I would advise you to do is obtain a good Family Law attorney, who will assist you at reasonable cost, file for a Modification of your Decree of Divorce, with a Motion requesting a DNA test to be performed as well. In light of the fact that there is a man who is already acting as father to your child, the Court may grant your requests. Not being the Judge on your case or having all the facts at hand, makes it hard to definitively answer your inquiry.

You need to speak with an attorney in your area about this. One of the strongest presumptions in the law is that when a wife gives birth the child is the husband's child. He can insist that the child is his. This has already been determined when you were divorced.

There are too many variables in facts that you have not provided to permit a simple answer to your question, including the fact that your chances of success may be different in one state than another it isn't clear what state law would control. Generally, it appears that the child was born while you were married - therefore your then husband is presumed to be the father unless the divorce decree found that he was not the father. If that did not happen, it may well be too late for you to challenge that failure of 4 years ago. You need to consult a lawyer in the state where you live to find out what options you have in attempting to challenge the presumption that he is the legal father. If a court will hear your argument and rule that he is not the father, then there are no parental rights to be terminated. However, if you are not able to now have court rule that he is not the father, you won't be able to terminate his parental rights except as a part of a step-parent adoption by your new husband. That may or may not be possible if your ex- won't consent to the adoption.