Yes. Custody and visitation are always modifiable; however, you must prove a material change in circumstances before getting to any changes (which the court will then look at the best interests of the children as to any new arrangement). What constitutes a “material change” varies widely and is case-specific, but some examples of likely qualifying changes are if the other parent has a substance abuse problem, is neglecting or abusing the children, has become seriously physically or mentally ill and is no longer able to care for the children, if there is a significant lack of supervision when with the other parent, or any major change in the situation requiring attention. Do not settle for verbal agreements between the other parent, they are not legally valid. Once a court order is in place, you need a modifying order entered by the court to make any changes enforceable by the court. You can certainly agree to one-time or temporary changes to visitation or custody, but without a replacement order, the other parent can dishonor any agreement reached.