In many states there is a waiting period for finalizing a divorce following the filing of the lawsuit for divorce. This waiting period is intended to allow the spouses to “cool-off” and reconcile if possible. And some states require the spouses to have separated and lived apart for some period of time before proceeding with the divorce. In some states that require such a separation period, if the spouses reconcile and begin living together again (cohabitating) after separating, the separation period must be restarted before the divorce process can proceed.

The waiting period or separation period is often 30-90 days but may be as long as 5-18 months in states such as Arkansas, California, North Carolina, South Carolina, and Vermont. These waiting periods are generally in addition to any minimum time period a spouse must have resided in the county in which the divorce is filed before filing for divorce—known as the residency requirement.

In Montana, there is no mandatory separation period before a divorce can be filed. However, there is a waiting period of 20 days from the date of filing the petition for dissolution of marriage before the divorce can be finalized, according to Montana Code Annotated § 40-4-107. This waiting period is designed to give couples a chance to reconcile if possible. It's important to note that Montana is a no-fault divorce state, meaning that a divorce can be granted without proving wrongdoing by either spouse. The only requirement is that the marriage is irretrievably broken. Additionally, at least one of the spouses must have resided in the state for 90 days immediately prior to filing for divorce, as per the residency requirement outlined in Montana Code Annotated § 40-4-104.