[Brad from Tennessee]

This can be determined through a (voluntary) blood or urinalysis. But if the insurer has no reason to suspect a potential policy holder smokes they would assume the “no” answer on the application was correct.

[virgil]

I can see people being charged with a federal felony for lying on their application or lying to their doctor. They could devise tests to see if you’re eating candy or beef brisket or potato chips or soda. It won’t stop with smoking. They could make cigarettes illegal right now if they wanted to, if it weren’t for the money they collect on taxes.

[Mike Darancette]

But if the insurer has no reason to suspect a potential policy holder smokes they would assume the “no” answer on the application was correct.

On "guaranteed issue" policies they don't ask health questions. In fact it is not an insurance company's business