In Re A.V‪.‬

Section 161.001(1)(Q) of the Texas Family Code provides that parental rights may be terminated if the parent has knowingly engaged in criminal conduct for which the parent is incarcerated and unable to care for the child "for not less than two years from the date of filing the petition." *fn1 We must decide whether the two years applies to the period before the filing or after, and whether the subsection is unconstitutional if applied to a parent who was incarcerated before the subsection's effective date. We hold that subsection Q's time period is prospective and that the subsection is constitutional even though applied to a parent incarcerated before the subsection's effective date. Thus, subsection Q is a valid ground for terminating the father's parental rights in this case. Because the father has not preserved any other claims that could be harmful error, we reverse the court of appeals' judgment and render judgment terminating his parental rights.