You'll want to speak with an attorney in your county since the answer to your question will depend on the specific facts of your case. There is not enough information in your question to give a specific answer, so this answer is aimed as general education.
You'll want to speak with an attorney because he or she can guide you through the process to obtain a new order concerning support or modification of an existing order concerning support.
You won't want to take any action before obtaining an order from the court to protect yourself. If you stop paying child support without a court order allowing you to do so, you could end up in serious trouble with the court.
Here's the Indiana Code section that applies to your question:
Termination or modification of child support; emancipation of child
Sec. 6. (a) The duty to support a child under this chapter ceases when the child becomes twenty-one (21) years of age unless any of the following conditions occurs:
(1) The child is emancipated before becoming twenty-one (21) years of age. In this case the child support, except for the educational needs outlined in section 2(a)(1) of this chapter, terminates at the time of emancipation, although an order for educational needs may continue in effect until further order of the court.
(2) The child is incapacitated. In this case the child support
continues during the incapacity or until further order of the court.
(3) The child:
(A) is at least eighteen (18) years of age;
(B) has not attended a secondary school or postsecondary educational institution for the prior four (4) months and is not enrolled in a secondary school or postsecondary educational institution; and
(C) is or is capable of supporting himself or herself through employment.
In this case the child support terminates upon the court's finding that the conditions prescribed in this subdivision exist. However, if the court finds that the conditions set forth in clauses (A) through (C) are met but that the child is only partially supporting or is capable of only partially supporting himself or herself, the court may order that support be modified instead of terminated.
(b) For purposes of determining if a child is emancipated under subsection (a)(1), if the court finds that the child:
(1) has joined the United States armed services;
(2) has married; or
(3) is not under the care or control of:
(A) either parent; or
(B) an individual or agency approved by the court;
the court shall find the child emancipated and terminate the child support.
As added by P.L.1-1997, SEC.8. Amended by P.L.2-2007, SEC.362.
Disclaimer: This answer is not intended to provide legal advice or to establish an attorney-client relationship. Please seek legal assistance from a competent attorney of your choice. This answer is intended for education only. The information provided may or may not be appropriate for your particular situation.