Custody and child support get discussed together because they usually get resolved together, but they answer different questions — one is about parenting time and decision-making, the other is about money.
Custody: legal and physical
Legal custody covers who makes major decisions about the child's education, healthcare, and upbringing. Physical custody covers where the child actually lives. Parents can share one, both, or neither, and a strong agreement spells out exactly how each works.
A parenting schedule is more than a calendar
Beyond the week-to-week schedule, a well-drafted custody agreement addresses holidays, school breaks, travel, and how last-minute changes get handled — the details that cause the most friction later if left vague.
Child support: calculated, not negotiated in a vacuum
Most states use a formula based on both parents' income and the custody split to calculate a baseline support amount. Agreements typically need to show the calculation, not just the final number, for a court to approve it.
What triggers a modification
A significant change in income, relocation, or the child's needs can justify revisiting either custody or support terms — building a clear modification process into the original agreement makes that easier later.