5 year old in trouble at school

My son is getting into a lot of trouble at school.  So much so, that my husband and I have to have a round table discussion with the principal, his teacher and the school social worker.  How can a kindergartener cause so much trouble?  They have (as I'm sure most schools do nowadays) the color system - start off green, move to yellow, orange and then red for everytime they do something wrong.  Red results in a visit to the principals office with a call home to the parents.  He has had 5 in 2 months of school.  He has been in a school setting since he was about 3, so school is not new to him.  He has had issues in each of his schools with the same type of behavior.  Not listening, interrupting, not following instructions.  I've asked his various teachers if they think that he has ADHD or something of that sort and I'm told no, that they worked with kids that have had it and he doesn't seem to have the same behavior.  I have not taken him to be diagnosed by a professional yet.  We have tried both taking things away as punishment and reward systems, but he never get's the reward because he is never that behaved to receive it.  For the most part at home he is great.  He is an only child and has grown up in a mature environment (we are "older" parents and never did baby talk to him).  So my biggest questions are:  What should we ask the school social worker and principal when we go in?  Is there a suggested place I should take him to diagnose him for ADHD or other(we just have a family doctor)?  Is there a counselor in my area of Golden, Colorado that deals with this kind of behavior?  Thanks for your time.

[Kevin Kennedy, Ph.D.]

You absolutely should be taking him to a mental health/behavioral health professional. Imagine that he had displayed a clear medical illness over a period of time. You would have taken him to the pediatrician right away. Often parents hold back from seeking professional help in the areas of behavior and emotions, but it is a mistake to hold back. Contact the Child Development Unit at The Children's Hospital in Aurora or the Colorado Child and Adolescent Mental Health Coalition (you can receive a list of resources from the Coalition).