There is a distinct difference between retroactive child support and child support arrearage:

A child support arrearage occurs when there is unpaid child support that is already owed.  The unpaid support is called an arrearage.  Basically, what has happened is that for whatever reason, the parent who has been ordered to pay support has gotten behind.

There may be a good reason for getting behind, such as a long illness, or a period when the person paying support has been out of work.  However, the support is still owed, and the arrearage must be paid.  Choosing to ignore the arrearage is never a good idea.  You may find your wages garnished when you least expect it or your income tax payment/ refund seized. Texas takes child support obligations very seriously and if it continues to go ignored there may be dire consequences that follow.

Retroactive child support occurs when there has been no previous child support order and the judge orders that child support should be paid from a previous time.  A good example of this is, if the child is a year old before the court case is filed, the judge can order child support from the birth of the child. There is a general presumption that it is reasonable for go back as far as four years, but the judge can go back ever further if he or she decides that it is in the best interest of the child.

If you have questions about your child support obligation, you should contact an experienced family law attorney to help you understand what your options are and what you should do about your particular situation.