There is no set age. When you are a minor, you can make your own medical decisions as soon as you are mature enough to make your own informed decisions and understand the consequences of your decisions. Generally, the treating doctor or other health service provider makes this determination. Because this is not a strict rule, there are many court cases about minors who want to make their own medical decisions. They have to ask the court to determine if they are mature enough to do so. Last Reviewed: November 2019