Child support is usually paid by the non-custodial parent to the custodial parent. While there are many exceptions and reasons to deviate from the basics because of higher income or shared and equal parenting arrangements the following provides some general information.
Child support in NY is until age 21 unless the child is emancipated sooner. Reasons for emancipation include the child marries, the child is in the military or the child no longer lives with either parent (college attendance is not an emancipation).
Child support is usually calculated by taking the non-custodial parent's income and deducting certain permitted reductions for child support paid for other children to a different parent, spousal support and social security taxes. For one child it is 17%, two children 25%, three children 29% and four children 31%.
The technical formula is more complicated and utilizes combined parental income but the above gives the basic approach. There are situations where the combined or single parent income is considered high and the court will not impose the percentage on the income that is viewed as excessive for the formula. That number will usually be reached on income over $250,000 but again like everything else there are exceptions and this is not a hard absolute number as there are many factors.
In addition to basic child support, parents are required to contribute to child care expenses incurred for work or educational purposes and medical insurance and expenses.
The receiving parent is not required to account for the usage of basic child support monies received, however the other expenses must be documented or by agreement as to amount.
Again, this is a very BASIC summary since there are exceptions and not all of the rules are explained. It is always in your best interests to consult with an experienced matrimonial attorney to see how the full rules will apply in your unique situation.