Maintenance is generally awarded to a spouse for the purpose of encouraging economic independence from the other spouse. The amount and duration of maintenance can be calculated using the Maintenance Calculator, however, people that are seeking an uncontested divorce usually have already decided how much maintenance is to be paid, if any, and are generally allowed by the Court to do so.
Maintenance is taxable income to the spouse receiving it, and tax deductible to the spouse that pays. Sometimes when one spouse makes very little income it makes sense to pay more maintenance than child support because it will benefit both parties. The payment to the lower income spouse may not trigger any tax consequences for the lower income spouse, and the paying spouse will get a tax deduction for the maintenance payments that were paid in any given tax year.
Maintenance is common when there is a significant disparity between the income of the parties. It is less common when each party is capable of self-support, or neither party makes enough money to reasonably make the payment. The payment of maintenance sometimes causes animosity between the parties because one party things they deserve it and the other does not. This is less likely, however, when one party will be doing most of the child rearing and is unable to work full time, or both parties agree that one parent should stay home with the children.