This is a very confusing and misleading name for what is actually a very simple policy. The policy is almost always permanent and does NOT expire at age 100. The 100 rather means that if the insured lives beyond age 100, premiums are no longer required, but on death the policy will still pay out. The insured simply pays into the policy until they pass away at which point the death benefit pays out. Premiums never increase and coverage never expires. This is the simplest and cheapest form of permanent insurance.