When your son answers YES to the question, "can someone else claim you as a dependent?" the software will take care of the healthcare issue. He won't be required to have the coverage because he already has it through you.
About the dependency issues, according to the IRS rule, if a person CAN be claimed as a dependent on someone else's return (a parent),he cannot get credits that you are entitled by not "allowing" himself to be claimed by you. Furthermore, not claiming him would cause you to lose credits that you can receive and to reduce your family size, as previously mentioned. So essentially it would be more tax to the IRS.
Here is a TurboTax article that discusses claiming dependents.
@danyell757
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