Yes I have a 9 year old son and he was having behavior problems at school and he was going down hill really fast so we got him changed to another school and now at this school he is like a different child they say he never does anything. Me and my husband have been married for 8 years and he has been with us basically all his life, we have 2 other children also. So now after 8 years his real father finally decides to step in and is taking me to court to try and get a change of custody. Can this happen even though my son has excellent records now at his new school but the father is going by the behavior he had at his previous school?

Does the biological dad want full custody or just access?
If he wants access on a weekly basis this can only be of benefit to your boy. Knowing his dad wanted him, however late, will be important to him as he gets older

He has been in his life what I meant by him just steping in is that he never had any interest in our sons schooling until he started having behavior problems at the other school and now he is taking it to court over his behavior and wanting to get a custody change.

What type of custody change?

He's wanting the court to change custody from me to him over this..
Sorry I'm just learning everything on here so bare with me if I don't do something right...

He is wanting to be the custodial parent over him instead of me

Mandie I think the court would judge in your favour. You done the correct thing changing your boys school. I can tell you are a loving parent. Maybe you could look into getting a child phychiatrist to help your boy through his troubles. Don't fight with the father, and allow him access. He must have concerns of some degree if he is seeking custody. Could you two meet and discuss it together on your own? Seeing you two fight won't be good for ue son

I agree with you but when we got a divorce the way they do it here is that both parents have the right to anything to do with their child's school and or medical records and he has found that out and I have my son in theraphy and he had an appt today and we took him only to find out that his father had called in and cancelled the appt.
He has visitation with him every other weekend and now that he has taken me to court to try and get the judge to change custody is just too much for all of us right now. I mean like I said my son has a wonderful home and a mother, stepfather and sibilings that love him so much and now that he has straightened up in school everything is going great until his dad came along and done this with the court... I just don't know what to do, it's worrying me sick that they will change custody from me to him over is past behavior problems.Thank you so much for communicating with me like this.

They be very unlikely to grant custody in his favour. Your son clearly has a good home and family. You must stop worrying, you will make yourself sick. Talk to your lawyer I'm sure they will tell you the same I am, that you will retain the custody. They won't move him when he is clearly well looked after.
Don't rise to any bait your ex throws at you, stay calm and polite with him. Prob just what he would like, is to show you up, as stressed etc.
Your lucky you have your partner for support, lean on him. And please don't worry.

Thank you so much I love having someone to talk with like this...

When he takes you to court over this take his records from the previous school and his records from his current school. Maybe even get some teachers from each school to be a "witness" for you or write a letter to the Judge so that he can see what you did was in the best interest of the son.

Tell the Judge he canceled the therapy appt
Even though he is at the new school include informing the dad in the things the way the court order says so he can't hold that against you.

Given the circumstances it's unlikely that any court would modify the existing custody order and grant custody to his father. Especially if you can document that there've been recent improvements in your son's conduct and performance in school, as a result of interventions by you and your husband.