Federal case closure criteria is set out at 45 CFR 303.11. There is a link to the CFR with this answer for you to review the material.
This information is provided for general educational purposes only including answers posted to questions asked. It is not intended to be relied on as legal advice. Your particular facts and circumstances must be considered to determine appropriate legal advice. Always consult with a competent attorney, licensed in your state, to discuss your particular situation. The material contained in this answer is provided solely for informational purposes. This information is not intended to create, and receipt of it does not constitute, an attorney-client relationship between you and the responding Attorney. The information in this answer is not guaranteed to be correct, complete or up-to-date. It should not be relied upon or construed as legal advice. You should not act or elect not to act based upon this information without seeking professional counsel. If you are also an attorney and you agree with the posted answer please check "I agree", if you are the party who posted the question and find that the answer is helpful or the best of what you have received please check the appropriate response.
Child support is a state law, in California there is no statute of limitations and it can be used to collect tax refunds and for the gathering of information on a parties income. This might not be answering your question as I am not really sure what your question is.
My name is Stephen R. Cohen and have practiced since 1974. I practice in Los Angeles and Orange County, CA. These answers do not create an attorney client relationship. My answers may offend I believe in telling the truth, I use common sense as well as the law. Other state's laws may differ.. There are a lot of really good attorneys on this site, I will do limited appearances which are preparation of court documents it is , less expensive. However generally I believe an attorney is better than none, but many will offer a free consultation and a face to face meeting generally will be better, I like my clients to write a short one page history of the fact and questions they have prior to meeting with them, so nothing is forgotten.