It is important to look into retirement accounts and pensions. They are sometimes worth a lot of money. So they are sometimes the most valuable thing that married couples own.
Some parts of retirement accounts may be divided in a divorce case. If a spouse pays into a retirement account or pension after the marriage has begun, but before the marriage is ended, at least part of that retirement account or pension is marital property. The part that is marital property can be divided by the court. It does not matter that only one spouse's income was paid into the account.
Not all retirement accounts can be divided by the court. And retirement accounts that can be divided by the court require a special order to divide them. And just because a retirement account is divided by the court does not mean that the money can be used right away by the spouse.
If retirement accounts are an issue in a divorce case, each spouse should talk to a lawyer. You should seek help and find out information about the accounts early in the case.