Adoption is a process that creates a legal parent-child relationship between the parties who do not have a biological parent-child relationship. Once the adoption is finalized, the adoptive parents and children have the same rights and obligations as legal or biological parents and children.
In a step-parent adoption, the child is adopted by one of the biological parents’ new spouse. That biological parent retains parental rights but the parent-child relationship is severed with the other biological parent. After that happens, the biological parent loses all rights to and responsibilities for the child. The adopting parent acquires these rights and responsibilities.