what are the implications of indicating one of my 18 year old dependents is disabled?

[Millshaf]

she has graduated homeschool but is disabled and cannot work or go to college. we did not indicate she was disabled while she was school age

[DoninGA]

If you indicate that she is disabled, then she would be eligible for the Dependent Care tax credit if you pay someone to care for her so that you can work.

[Bsch4477]

Since she is under age 19 it has no effect on your tax liability in 2025. Be sure to check the box saying that she is disabled next year.