In a general sense, commingling is when two things get mixed together. They have been commingled and it can be difficult to sort them apart again.
When it comes to divorce, this term is most often used when talking about separate property and marital property. In some cases, an item that starts out as separate property can be commingled, making it into marital property. Changing the status means that the spouses have to split it up as they go through the property division process.
How would this happen?
For an example of how this could happen, consider if you were given a substantial inheritance from your parents. You were already married at the time, but it still counts as a separate asset because it is a direct gift to you, so it is different than wages or other types of earnings.
If you keep that inheritance separate, such as opening your own investment account and simply investing the money for the future, then it doesn’t have to go through the property division process. You can just get divorced, split up everything else you own, and keep the entire inheritance yourself.
If you put the inheritance in a shared account, allow your spouse to access or use the inheritance, or purchase shared assets with it, this commingles the inheritance with your other financial assets. If you just mixed the inheritance into an investment account you already opened with your spouse, for example, or if you used the money as a down payment on a family home, then the inheritance would have to go through property division.
This process can get a bit complicated, so make sure you know about all the legal options you have at this time.