In many countries alimony, maintenance or spousal support is an obligation established by law that is based on the premise that both spouses have an absolute obligation to support each other during the marriage (or civil union) unless they are legally separated, though in some instances the obligation to support may continue after separation. Once dissolution proceedings commence either party may seek interim or pendente lite support during the course of the litigation.

Where a divorce or dissolution of marriage (civil union) is granted, either party may ask for post-marital maintenance (also known as alimony or spousal support). It is not an absolute right, but may be granted, the amount and terms varying with the circumstances. If one party is already receiving support at the time of the divorce, the previous order is not automatically continued (although this can be requested), as the arguments for support during and after the marriage can be different.

Some of the possible factors that bear on the amount and duration of the support are:

• length of the marriage
• time separated while still married
• age of the parties at the time of the divorce
• relative income of the parties
• future financial prospects of the parties
• health of the parties
• fault in marital breakdown

Unless the parties agree in a binding written instrument, the court will make a fair determination based on the legal argument and the testimony submitted by both parties. This can be modified at any future date based on a change of circumstances by either party on proper notice to the other party and application to the court. In some jurisdictions the court always has jurisdiction to grant maintenance should one of the former spouses become a public charge.

Alimony should not be confused with child support, which is the obligation of a non-custodial parent to support the child(ren) of a former relationship.