You may have seen this in a divorce judgment, parenting plan, school form, or a text saying one parent has "full custody" and the other has "joint custody." Usually, that wording is trying to separate two ideas: who makes major decisions for a child and how parenting time is shared. Sole custody generally means one parent has primary authority over big decisions or primary physical care. Joint custody usually means both parents share decision-making, parenting time, or both. The catch: people often use those labels loosely, and the labels do not always match the legal reality.

In Illinois, that old custody language is mostly outdated. The Illinois Marriage and Dissolution of Marriage Act was revised in 2016 to use allocation of parental responsibilities and parenting time instead of "sole" and "joint custody." So when someone says "joint custody," they may mean shared decision-making, equal time, or just that both parents stay involved. Those are not the same thing.

That difference matters in real life. A parent may have most overnights but still share major decisions about school, medical care, and religion. Bad advice often treats "sole custody" like automatic control over everything. It usually is not that simple.

It can also affect an injury claim involving a child. The parent with authority over major medical or legal decisions may be the one dealing with records, treatment choices, or settlement steps, though court approval is often required for a minor's settlement regardless.