Children age 18 or over can buy life insurance on their parents, because insurable interest does exist between parents and their kids.
Insurable interest basically means you rely on the other person for financial support, of you may suffer financially if the person you want to insure were to die.
In addition, you may need your parent's permission, signature on the application for life insurance, and your parents may need to answer some health questions.
However, some insurers may offer life insurance plans that do not require the insured person to know about the life insurance policy.
Learn more about how to buy life insurance for your parents.