You do not have to be legally separated to file for divorce on fault grounds in New York. However, these grounds have certain other requirements that you must meet. If you file based on cruel and inhuman treatment, you must do so within five years of his bad behavior. If your spouse is incarcerated, you can use this as a ground, but only if he was imprisoned for at least three years, and if his release was not more than five years ago. Adultery is a ground, but this also must have occurred within the last five years, and you must produce a witness to testify to your spouse’s infidelity. Abandonment is also a ground in new York, but it means that your spouse has left you, so you must live apart for this ground to apply. New York does not consider marital misconduct when dividing property, so there’s no financial downside to filing on a fault ground. Except for abandonment grounds, you can get your divorce under way while you’re sharing the same roof.
New York’s October 2010 no-fault ground is irretrievable breakdown of the marriage. You don’t have to live separately to have a no-fault divorce. However, you must reach an agreement regarding property, support and custody before a New York court will grant you a no-fault divorce. Such an agreement is identical to a separation agreement in content. The basic difference is that you and your spouse don’t have to live apart to draft a marital settlement agreement; you can file for divorce on this no-fault ground and continue to live together while you work out an agreement. You can be divorced as soon as you've done so.
One of New York’s grounds that requires separation is a “conversion” divorce. This is not a legal term, but a description of its concept. It applies when you and your spouse sign a separation agreement, file it with the court, then one of you moves out and you proceed to live separately. After one year, either of you can petition the court to convert your separation agreement into a divorce judgment. You're using the fact that you’ve been separated under the terms of the agreement for at least one year as your divorce ground.
Legal Separation Ground
Although not all states do, New York recognizes the concept of legal separation. This option is very similar to signing and filing a separation agreement with the court, but with a legal separation, you actually have a judgment or decree of separation. Some spouses may not want to sever the marital tie entirely for religious reasons or for insurance purposes; you generally cannot cover your spouse on your health insurance policy after you're legally divorced. The court mandates all the same requirements for a legal separation as a divorce judgment. As with a conversion divorce, either spouse can petition the court to convert the legal separation to a legal divorce after a year if circumstances change or one of them changes his mind. However, this is more of a long-term option if spouses don't intend to actually divorce in a year or so.