Getting remarried does not, on its own, change an existing child support or custody order. Both types of orders generally stay in place exactly as written until a parent asks a court to modify them and the court agrees a change is warranted. Remarriage can sometimes be part of the reason a modification is sought, but the marriage itself is not treated as an automatic trigger.
Child support and a new marriage
A new spouse's income is not typically counted directly against, or in favor of, either parent's support obligation. Courts generally continue to base support on the two parents' own incomes and circumstances. Where remarriage can indirectly matter is if the remarriage coincides with other genuine changes, such as the birth of additional children in the new household, which a parent might later raise as part of a separate request to modify support.
Custody and a new household
Remarriage alone is rarely enough to change a custody arrangement, because courts favor stability for the child and generally will not reopen custody just because a parent has a new spouse. What can become relevant is how the new household actually affects the child, such as a new stepparent's documented history of violence or substance misuse, a move required by the remarriage, or real changes to the child's schooling or daily routine.
The difference between "relevant" and "automatic"
It is worth separating two ideas that often get blended together. A remarriage can be relevant background to a modification case. It is not, however, a standalone legal basis that automatically reopens custody or support. A parent still has to file a request, and a court still has to find that circumstances have changed enough, and that a new arrangement would serve the child's best interests, before anything in the existing order changes.
Why this matters for a case
Whether a specific remarriage, or the circumstances surrounding it, would support a modification request is a case-specific question. A licensed family law attorney can evaluate the details of a particular custody or support order and advise on next steps.