Under current law, California does not allow more than two legal parents per child. But with the rise of surrogate births, same-sex parenthood, and assisted reproduction, California state senator, Mark Leno, introduced Senate Bill 1476, which would allow a child to have multiple parents. The bill states that in a situation in which three or more people could not agree on child custody, a court could divide custody among all of them.
The bill does not require a judge to take this step, but it provides another avenue when trying to decide what is in the best interest of a child. California’s children might ultimately benefit from additional financial support, health insurance, or social security benefits from more than two parents. Supporters of the bill believe this factor might ultimately reduce the state's potential financial responsibility. Opponents argue the bill is redefining and "muddy[ing] the waters" of family structure. It may also have unintended consequences in other areas of the law, such as inheritance or wrongful death. It will be interesting to hear the issues raised by this bill, and if it is signed into law, how it impacts families.
We are not aware of any Colorado law which would authorize more than two legal parents for purposes of determining child custody or child support issues. However, Colorado has changed state intestacy statutes to allow for a person to inherit from more than just two parents (adoptive and birth parents, under certain situations). This statute does not impact Colorado law regarding child support or child custody.
See Jim Sanders, California Bill Would Allow a Child to Have More than Two Parents, The Sacramento Bee, July 2, 2012.