General insurers 
General insurance companies offer indemnity policies or reimbursement health plans Mediclaim has to be renewed on an annual basis. The company can increase the premium at renewal Look for the clause on sub-limits. The most common sub-limits are room rents, doctors’ fees and diagnostics Individuals from a small town should go for a cover of 2-3 lakh, and in metros up to 5 lakh. 
Life insurers 
Defined benefit plans, mostly offered by by life insurers, pay a lump sum on the diagnosis of any of the named critical illnesses listed in the policy document Insurers usually do not cover the specified critical illnesses if they are diagnosed within 90 days from the effective date of the policy Premiums are usually revised at renewal, which is usually three years or more If the company wants to increase the premium within three years, the insurer has to seek Irda’s approval