Custodial parent has moved out of state and I’m on child support in maryland?

Assuming you no longer live in Maryland, you question whether a Maryland child support order still applies since your wife's relocation outside of Maryland. That is not against the law, it is the law! Maryland (like most other states) adopted the Uniform Interstate Family Support Act that gives the original state continuing, exclusive jurisdiction to enforce or modify its child support order unless all parties consent to submit the case to another state where at least one of the parties now resides with the child. This discourages parties from relocating to reduce child support. Very technical area of the law - consult an attorney!