There are eight grounds for divorce in New York as follows -
1. Abandonment of one spouse by the other. The spouse must have left the marital residence for a period of at least one year, without cause or justification and without the consent of the abandoned spouse, and never returned.
2. Lock-Out. One spouse locked the other out of the marital residence for more than one year, with no intention of permitting the other to return.
3. Imprisonment. One spouse can sue the other spouse for divorce if the latter has been sentenced to prison for a period of three years or more consecutive years after the marriage.
4. Adultery. Where one spouse has been unfaithful to the other. The divorcing spouse must produce independent corroborating evidence of the betrayal, such as witness Affidavits, investigator's photographs, video or audio tapes. This ground cannot be used if more than five years have passed since the discovery of the adultery, or if a reconciliation has occurred.
5. Cruel and inhuman treatment. This ground can be used by an abused spouse where the abusing spouse has mentally and physically abused the former, endangering the physical and mental well- of the abused spouse, making it unsafe and dangerous for the abused spouse to continue to live with the abuser.
6. Legal Separation Agreement. This is a written contract between the spouses agreeing to a separation and determining division of property, child custody, support and visitation, among other terms agreed by the parties. As long as both parties have resided separate and apart for a period of more than one year, and have adhered to the terms of the Agreement, then either party can institute divorce proceedings against the other based on the Agreement.
7. Constructive abandonment. One spouse without cause or justification has refused to have sexual intercourse with the other for a period of more than one year.
8. Irretrievable Breakdown - Where the relationship between the spouses has irretrievably broken down for a period of at least six months, with no hope of reconciliation. This is a no-fault ground for divorce, similar the "irreconcilable differences" in all the other states in the US. California was the first state to introduce no-fault grounds for divorce.
Most divorces are now filed in New York courts using this ground, which was introduced by the legislature in New York State in 2010.