child support up until the age of 20 age of majority Child Support Laws Termination of Child Support- Age of Majority. almost every part age of majority almost every part the child turns 18 at age 18 eligibility for child support almost every part NCSL.org: Terminating Child Support almost every part majority age of 18 age 18 almost every part support payments Child Support Termination Age almost every part Child Support Termination Age almost every part