@1914gd You lose the child tax credit when a child turns 17--no exceptions. And you should still be fine to claim an 18 year old high school student as a "qualified child" dependent for earned income credit. Have you entered all of his information in MY INFO correctly?
Make sure you have entered your child as a dependent in My Info, and that you have entered the child's Social Security number. Careful— do not say that your child’s SSN is not valid for employment. If your child was born in 2024 make sure you said he lived with you the whole year. There is an oddly worded question that asks if the child paid over half their own support. Say NO to that question.
If he is entered correctly as your dependent, then when you enter your income earned from working, the earned income credit should be added automatically to line 27 of your tax form.
https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-credits-deductions/qualifications-ea...
https://www.irs.gov/credits-deductions/individuals/earned-income-tax-credit/use-the-eitc-assistant
Look at your 2024 Form 1040 to see the child-related credits you received
PREVIEW 1040
https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/preview-turbotax-online-retur...
Child Tax Credit line 19
Credit for Other Dependents line 19
Earned Income Credit line 27
Additional Child Tax Credit line 28
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**