If you and your spouse have children the parent with whom the children do not reside will probably be paying child support to the other.

Pursuant to the Child Support Standards Act (CSSA) (or by agreement acknowledging what the CSSA amount would have been and, if you deviate from that amount, the reason for your deviation) New York law uses combined parental income as the prime measure to calculate child support. Expenses of a non-custodial parent are virtually ignored. The below simplifies NY law which adds in and then separates out the income of both spouses.

        Step 2: Multiply the non-custodial parent's income by the following percentages:

The result is the "presumptive" amount of child support to be paid for everything except child care, medical and educational expenses.

Child care expenses (resulting from employment), medical, and educational expenses will usually be pro-rated in proportion to the parent's income.

The courts may ignore all of the above for any good reason (they must, however, set the reason forth in their decision). The parties may, by agreement, ignore all of the above for any reason, so long as it is described in the agreement, and so long as the amount required by the Guidelines is also spelled out.

Neither parent has any obligation to support a child once the child reaches 21 years of age (although it is not unusual for child support to continue until age 22 if the child remains a full time college student). Child support may end before 21 years of age under certain circumstances such as the gainful employment of the child or the child's willful refusal to maintain a relationship with the non-custodial parent. However, generally, although children no longer are minors at 18, parents are obligated to support them until they are 21.

NOTE: Domestic Relations Law § 236 [B](9)(b) was amended effective October 13, 201 to add to the "substantial change of circumstances" as the  basis for modification of child support orders to provide two new bases for the modification of an order of child support: (1) the passage of three years since the order was entered, last modified, or adjusted; or (2) a 15 percent change in either party's income since the order was entered, last modified or adjusted provided that any reduction in income was involuntary and the party has made diligent attempts to secure employment commensurate with his or her education, ability and experience. The parties may specifically opt out of the two new bases for modification in a validly executed agreement or stipulation. This provision provides that incarceration is not a bar to finding a substantial change in circumstances under certain conditions. This change represents  a major change to existing law and will serve to assure that child support awards remain reflective or the parties' income. This change is applicable only to child support orders which incorporate but do not merge stipulations or settlement agreements if the stipulation or agreement was executed on or after the effective date of the bill.