The answer to this question depends on a few different factors. First, it depends on whether or not you are currently enrolled in your parents' insurance plan. If you are enrolled in your parents' insurance plan, then you will lose your insurance the day you turn 26. However, if you are not currently enrolled in your parents' insurance plan, then you will not lose your insurance the day you turn 26.
There are a few other things to keep in mind as well. First, even if you lose your parents' insurance the day you turn 26, you may still be eligible for other types of insurance, such as through your employer or through the marketplace. Second, if you have a pre-existing condition, you may be eligible for insurance through the marketplace even if you are not currently enrolled in your parents' insurance plan.
If you have any other questions about your insurance, you can contact your insurance company or the marketplace directly.