If a custody order is already in place, how can I get it changed?
Because custody is decided based on what is in the best interest of the child, an order is never permanent. If you have a final custody order already in place, you can petition the judge to make changes to it (modify it) only if there has been a substantial (significant) change in circumstances since the custody order was issued. The judge may modify the custody order if, based on these new circumstances, s/he feels that the modification would be in the child’s best interests.*
However, if you are looking to modify or terminate a joint custody order, the judge may do so if you can show it is in the best interests of the child without showing a substantial change in circumstances.** Also, if both parents request it, a custody order giving one parent sole custody can be changed to a joint custody agreement if it’s in the child’s best interests.***
* See, for example, In re Marriage of Lucio, 161 Cal.App.4th 1068 (2008); In re Marriage of Burgess,13 Cal.4th 25, 913 P.2d 473 (1996)
** See Ann.Cal.Fam.Code § 3087; see, for example, Niko v. Foreman, 144 Cal.App.4th 344 (2006)
*** See Ann.Cal.Fam.Code § 3088