Washington (CNN) -- A same-sex couple has asked the Supreme Court to intervene in a cross-state dispute over their efforts to have both of them officially listed as the parents of an adopted 5-year-old boy.
The California couple filed an appeal this week with the high court, saying Louisiana, where the child was born, has an unconstitutional policy against adoption by unmarried couples. The state used that policy to justify naming only one of them on an amended birth certificate.
The men, Oren Adar and Mickey Ray Smith, argue that gay couples have a due process right to be listed on such certificates as joint custodial parents. A federal appeals court has ruled against the couple.
The case could have broader implications in the current legal fight in state and federal courts over same-sex marriage and whether states -- and Washington -- must honor legal rights that gays and lesbians enjoy in other states.
The men, who live in San Diego, had legally adopted a year-old boy from Shreveport, Louisiana, in 2006. The adoption was finalized in New York state, where the couple was then residing.
In their appeal, spearheaded by the gay rights advocacy group Lambda Legal, the couple said it is important both practically and symbolically that they both be listed as the legal parents.
"Obtaining an amended birth certificate that accurately identifies both parents of an adopted child is vitally important for multiple purposes, including determining the parents' and child's right to make medical decisions for other family members at the necessary moments; determining custody, care, and support of the child in the event of a separation or divorce between the parents," the legal brief said.
Lawyers for the men also said it is vitally necessary for Social Security and tax purposes, inheritance, insurance, school registration, and obtaining a passport.
Adar and Smith tried to have the birth certificate changed in Louisiana. All states have laws creating a right to accurate, amended official birth and identity documents that would be recognized in other states and by the federal government.
Darlene Smith, Louisiana's registrar of vital records and statistics, refused their request. She took the position that the term "adoptive parents" in the applicable section of state law applies only to married parents, because in Louisiana, only married couples may jointly adopt a child.
Louisiana state officials argue they have not refused to recognize the New York adoption decree, and had offered to list one of the parents on the official amended birth certificate. But Adar and Smith insisted both of them should be named.
The 5th Circuit U.S. Court of Appeals ruled in April that Adar and Smith cannot file a federal civil rights claim under the Constitution's "full faith and credit" clause. That refers to Article IV, Section 1, which says states must respect the "public acts, records, and judicial proceedings of every other state."
The full 16-member court, in an 11-5 ruling, concluded the clause applies only to court actions, not those of state legislators or executive officials, and added that "there is no legal basis on which to conclude that failure to issue a revised birth certificate denies 'recognition' to the New York adoption decree."
More importantly, the court said states have the power to make their own decisions about issuing birth certificates.
"Adoption is not a fundamental right," said the appeals court, citing studies that found marriage provides a more stable environment in which to raise children.
"Louisiana has a legitimate interest in encouraging a stable and nurturing environment for the education and socialization of its adopted children. ... Louisiana may rationally conclude that having parenthood focused on a married couple or single individual -- not on the freely severable relationship of unmarried partners -- furthers the interests of adopted children."
The Supreme Court is likely to decide in late September whether to accept the case for review. If it does, oral arguments would likely be held early next year, and a ruling would come some weeks afterward. A decision by the justices not to intervene would be a final legal defeat for Adar and Smith on the certificate question, but would not affect their continuing custody of the boy.
The case is Adar v. Smith, State Registrar (11-46).