Establish paternity

If the alleged father of your child doesn't recognize voluntarily his son as his own, and you want to formalize paternity, you should contact your local Office of Child Support Enforcement.

The process for establishing paternity in cases of IV-D includes: meeting with the mother to discuss the process for establishing paternity.
Having the parent sign a statement indicating the identity of the alleged father.
Finding the supposed father. This is done using resources provided by various government agencies, including the Internal Revenue Service (IRS), the social security administration (SSA) and the Department of Defense (DOD).
Contacting the supposed father and give you the opportunity to voluntarily acknowledge paternity.
Asking all parties-the alleged father and mother and child-undergo genetic testing.(Note that if the alleged father is not present to genetic testing, it can be determined as being the father of the child by default).
Inform the alleged father of fatherhood.
Test results indicate that the supposed father is the biological father of the child, and he does not dispute the results, these results would then be recognised as a conclusive determination of paternity after 60 days.
References:
Establishment of paternity. Office of Child Support Enforcement. 8 July 2007 [http://ocse.acf.hhs.gov/necsrspub/training/paternity/hhspe.htm].