A top-up policy is different from a base policy, and policyholders often buy it to enhance their insurance coverage. But, are these top-ups available on critical illness policies? The answer is ‘Yes’. One can purchase a top-up policy over the base health insurance policy or even a critical illness policy. A top-up policy acts as an add-on to the insurance coverage to the base policy to provide better financial protection to the policyholder. While a basic health insurance policy covers the expenses incurred for medical treatment, a critical illness policy provides a lump sum payout upon the diagnosis of a critical illness, such as paralysis, cancer, kidney failure, heart attack, etc.