Not every state allows legal separation. However, you can obtain a legal separation in the District of Columbia.  A legal separation is accomplished by petitioning the court, usually on the same grounds as for a divorce. The separation petition may include a request for division of assets and child custody and support, as well as spousal support. 

The court-decreed right of separation allows parties to remain married while living apart. The parties may not remarry during a legal separation. Spouses also may come to their own agreement to separate for a period of time, if they are not able to make the decision to divorce.  You do not need a legal separation in order to file for divorce.