Yes, Life insurance companies can refuse to pay the death benefit of your life insurance policy if it is within two years since the policy was purchased, and they find that you misrepresented facts on the application for life insurance coverage when you applied for your policy.

For example, if the applicant for life insurance was scheduled for a biopsy for cancer, but answered "no" to the question that asked if there were pending tests for diagnosis of any disease.

If the health questions on the application for your life insurance are answered honestly, the life insurance policy will pay out the death benefit upon your death, because they base their approval for payout upon what is written on the application. 

The life insurance company will not pay out a death claim if death by suicide occurs during the first two years of the life insurance policy (one year in some states like Colorado) , or if there are explicit exceptions on a particular life insurance policy, for example, exclusions for death by sky diving.

Some life insurance policies will exclude payment if death is caused by piloting a private plane, but that is almost always spelled out in an amendment or rider to the life insurance policy.