(a) If a child has an acknowledged father, a signatory to the acknowledgment or denial of paternity may commence a proceeding under this chapter to challenge the paternity of the child only within the time allowed under Section 160.308.
(b) If a child has an acknowledged father or an adjudicated father, an individual, other than the child, who is not a signatory to the acknowledgment or a party to the adjudication and who seeks an adjudication of paternity of the child must commence a proceeding not later than the fourth anniversary of the effective date of the acknowledgment or adjudication.
Official text of the Texas Family Code as published by the Texas Legislative Council.