Legal decision making in Arizona (formerly known as "custody") usually refers to how major decisions about a child's healthcare, education, and (sometimes) religion will be made, but within those broad categories, most of the issues that crop up between parents are actually about far more specific disagreements. Recently, a dispute between Michigan parents about whether and when to vaccinate their child boiled over into a citation for contempt and a jail sentence for the child's mother.
As reported here [http://www.bbc.com/news/world-us-canada-41504796], Rebecca Bredlow and her ex-husband James Horne had a son in 2008 and initially agreed that they would space out his vaccinations instead of having them done all at once (which is a common medical practice). Rebecca and James separated shortly thereafter and were granted joint custody (which in Arizona would be called joint legal decision-making authority), meaning neither could make a major medical decision without the other's permission.
A few years later, James wished to have additional immunizations administered to the couple's son but Rebecca strongly disagreed, and so the couple had to get the family court involved. After a hearing, the court ordered Rebecca to have the additional shots administered to the child but she refused, prompting the court to hold her in contempt and to sentence her to 7 days in jail for violating the court's order. Rebecca was quoted as saying that she was willing to go to jail rather than violate her beliefs by having her son vaccinated, though one can't help but wonder if she took any solace in her principled stand because the court also awarded James temporary sole custody of the child so that he could have the immunizations performed.
It's likely that the parents would have faced similar difficulties in Arizona. Arizona, like Michigan, generally allows parents to decide whether or not to vaccinate their children, but in a joint legal decision-making parenting plan, neither parent can take a step like that against the wishes of the other, which leads parents who cannot agree inexorably to the courtroom. In this type of situation, rather than deciding whether or not the child is to be vaccinated, the judge may simply decide which parent gets to make that decision (e.g. giving one of the parents sole or final decision making authority over medical decisions.
It's unfortunate that these parents did not resolve this issue among themselves back in 2008 when they were on better terms. By forcing the court to make a decision, the parents gave up their opportunity to craft a precise compromise solution and instead forced the court to use the blunt instruments of contempt and sole custody to decide the issue-a valuable lesson for Arizona parents and family law attorneys alike about the value of a well thought out parenting plan.