Navigating family law in the San Francisco Bay Area means dealing with some of the most technical regulations in the country. California recently updated its support guidelines, but many common myths about “automatic” custody remain. Here are five essential things you should know about the current legal landscape.
1. There is no automatic 50/50 custody presumption
A common misconception is that state law now defaults to an equal time split. In reality, under California law, there is neither a preference nor a presumption for or against any specific custody arrangement. Instead, the court has the widest discretion to create a parenting plan based solely on the best interests of the child, prioritizing health, safety and welfare above all else.
2. California uses a unique algebraic formula
California continues to use a complex algebraic guideline formula. This calculation factors in each parent’s net disposable income and the percentage of time the higher-earning parent has physical responsibility for the child. Since the cost of living varies significantly across California and exceeds the national average in many regions, including the San Francisco Bay Area, Los Angeles, and Sacramento, the formula has been updated to better reflect the financial realities families face statewide.
3. The new rule for sharing “add-on” costs
One of the biggest shifts under recent 2025 reforms involves “add-on” costs like childcare for work and uninsured medical expenses. Previously, these were split 50/50 by default.
Now, under California law, this rule has been reversed. The court must now divide these expenses in proportion to each parent’s adjusted net disposable income. While you can still request a 50/50 split, it is now the exception rather than the rule. This shift places more financial responsibility on the parent with the higher income.
4. The moving parent holds the “right to move”
If you have sole or primary physical custody, state law generally grants you a presumptive right to change the child’s residence. The burden of proof is not on the person moving; rather, it is on the non-moving parent to prove that the move would be detrimental to the child.
However, if you share joint physical custody, the court will look at the case “de novo.” This means they will re-evaluate the entire custody plan from scratch to see if the move serves the child’s best interests.
5. Proving a parent could earn more
If one parent believes the other is intentionally earning less than they could, they may ask the court to “impute” income. However, under California law, the burden of proof lies with the person asking for the imputation.
You cannot simply claim the other parent is “lazy.” You must provide evidence that they have both the ability to work and the actual opportunity (specific job openings in the local market) before the court will calculate support based on phantom earnings.
Taking the right steps for your family
Because the legal standards for move-aways and income imputation are so evidence-heavy, preparation is the key to a favorable outcome. If you are navigating a transition and want to ensure your parenting plan and support orders are accurate, consider speaking with an attorney to review your specific financial and custodial goals.