Everything that a spouse acquires from the day that the marriage occurred to the day that a Petition for Dissolution of Marriage is filed is marital by default. That includes assets and liabilities, however they are titled. We start with the assumption that all of those things are marital and thus part of the marital estate. Of course, there are many exceptions to that general rule that simply looks at the specific beginning date of the marriage and the presumptive end date. But, ignoring the exceptions for the time-being, if “it” was acquired during the marriage it is marital.
The marital estate can also be made up of things acquired before the marriage or after the filing date of the Petition, but generally those nonmarital assets and liabilities that become marital do so because of actions by the spouses during the marriage. For example, one spouse could own a home before the marriage, but during the marriage they may make a gift of the home to the marriage by changing the title to include both spouses.
A spouse may acquire nonmarital assets and liabilities during the marriage through gift or inheritance. Assets acquired in that manner, though, can often be commingled with marital assets, which can alter the status to marital.Nonmarital assets can accrue value during the marriage, which accrual can be considered marital. For example, a spouse may own a brokerage account before the marriage that increases in value due to the efforts of that spouse in actively trading stock etc. in the account. Passive increase in valuation typically is excluded from becoming marital.
Prenuptial (antenuptial) agreements may specify that certain items are or are not marital.
What is and what is not part of the marital estate is determined by the divorce court, and after the estate is determined, it is divided, usually equally (but, again, there are exceptions). Contact an experience family law attorney to discuss your matter specifically.