Does a life insurance policy become void if the insured goes to jail?

Generally, no. However, the fact that you are in jail does not excuse making the premium payments on the policy. Therefore, the policy may lapse (terminate) for non-payment of premium if payments are not made.

Jail may enter the picture in another way. If the person who goes to jail is the beneficiary on the policy, and the incarceration is because the beneficiary killed the insured, the beneficiary will not be able to collect the life insurance proceeds. A person such as he/she will not be permitted to benefit from the wrongful act of killing the insured.