Need only two classes to graduate next semester, but need four classes to be covered under health insurance?

I only need two classes to graduate next semester, however, I need four classes to be considered a full-time student, and be covered under my fathers health care insurance. I am covered under Cal-vet which pays for any tuition expense, meaning I don't pay per unit. Do I only need to show proof of full-time once at the beginning of semester? or do they check. I really do want to go to classes that I don't need to go.
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If you are not a full time student and your father leaves you on his insurance and it is provided by his employer, then if you get caught he will probably be out of a job. Not worth it. Take the classes.
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