Child support isn't taxable income on any state return, or on the federal return.
Assuming you are going through the questions for the Pennsylvania Special Tax Forgiveness Credit, PA may require you to enter it:
Child support (included in child’s eligibility income, not the parent’s eligibility income).
http://www.revenue.pa.gov/FormsandPublications/FormsforIndividuals/Documents/Personal%20Income%20Tax...
So.... the short answer is NO- if this is your tax return.
If, as a hypothetical example, your 16 year old daughter was completing her return, then the child support that is meant for her is used to calculate her Special Tax Forgiveness Credit. Child support is not the parent's income for this purpose.
