Reinstating a Policy
If your policy has terminated due to non-payment of premium, you may receive an offer from the insurance company to reinstate your policy.
Evidence of insurability may be required (i.e. answering medical questions) and well as paying any outstanding premiums.
Reinstating a policy can make sense for certain types of insurance (e.g. life insurance) in order to preserve the age (and guaranteed premium) that the policy was originally issued for. If a formerly insured person's health has changed since the original effective date of the policy, it may preclude them from being able to reinstate the policy successfully, and the insurance company may ask that person to reapply.
An insurance advisor can assist you with this process.