At the same time an unprecedented Supreme Court ruling in 2015 made it necessary for all states to recognize gay marriage, it also did the same for same-sex spouses wishing to separate. When a same-sex couple wishes to divorce, all states must recognize that divorce, with certain stipulations. Prior to that ruling, however, those states that recognized gay marriage permitted non-resident gay couples to divorce in their states as well, including California.
There still may be instances, however, where married same-sex couples may have problems getting divorced. Those who couldn't get married legally and who instead opted for civil unions may have trouble having those unions dissolved in some states. State-by-state government responses are questionable in these cases. Same-sex partners who have complex unions might do well to speak with a lawyer in their state regarding the dissolution of their marriage or partnership.
For instance, couples who are in civil unions might have to live in the state where the civil ceremony was performed to have the union dissolved as opposed to those who were legally married and who can now be granted a divorce in any state. As for California, one spouse has to have resided in the state for at least six months before filing for divorce. For same-sex couples, the state will hear a petition for divorce if the couple married in the state but neither lives in the state at the time of the filing of documents. They must, however file for divorce in the same county where they were married.
The rules that govern same-sex divorce can still be confusing. A California lawyer will know state family laws and how they pertain to same-sex unions and divorce. Getting such an attorney's advice would likely be the best place to start the same-sex divorce process.
Source: findlaw.com, "Same-Sex Divorce: What You Need to Know", Accessed on Dec. 1, 2017