A legal separation, which is sometimes called separate support or separate maintenance, is a lawsuit for support while the spouses are living separating and apart.

All states except Alaska, Delaware, Florida, Georgia, Idaho, Mississippi and Pennsylvania permit couples to legally separate, sometimes as a preliminary to divorce and sometimes as an end in itself.

In obtaining a legal separation, the couple normally follows all the steps they would in obtaining a divorce. The couple must write a separation agreement, which is reviewed by the court. The agreement spells out the terms and conditions of spousal support or maintenance, child custody and visitation, property division and responsibilities for insurance coverage.

Couples who separate this way normally no longer file joint income tax returns.

Social Security rules permit former spouses married ten years or more the right to receive benefits based on the other’s earning history, so a decree of legal separation can be used to "buy time" to meet the ten-year rule.

In some jurisdictions, legally separated spouses retain the right of inheritance.

The salient difference between a legal separation and a divorce is that in a legal separation the couple remain married and neither is free to remarry. Very often people obtain a legal separation as a preliminary to a divorce because the "language of "legal separation’ is simply more comfortable and less imposing."

A divorce a menus et thoro ("from table and bed") is used in some jurisdictions to describe a legal separation, which does not dissolve the bond of matrimony. Instead it only settles all issues including, but not limited to, property, debt, alimony, support, visitation that would normally be resolved when a marriage ends in divorce. A divorce a vinculo matrimonii ("from the bond of matrimony") is a final divorce. One will often see this expression in the final divorce decree or judgment, which is the document, once signed by the judge, that terminates the marriage.