Presumption That Parent to Be Appointed Possessory Conservator
Conservatorship, Possession, and Access · Parent Appointed as Possessory Conservator
The court shall appoint as a possessory conservator a parent who is not appointed as a sole or joint managing conservator unless it finds that the appointment is not in the best interest of the child and that parental possession or access would endanger the physical or emotional welfare of the child.
Official text of the Texas Family Code as published by the Texas Legislative Council.