There is nothing like portablility and non-portability in Health Insurance. Any Insurance Company is OK because all are equally bad. But make sure that you purchase the policy directly from the company so that you can sue them later if found deficient without having to sue the agent as well.

If you continue with any other Insurance company, so long as you keep the documents of previous years insurance with any company, you will get the benefit of coverage for pre-existing diseases. It is not necessary as per law that you have to be with the same insurance company to claim the expenditure of treatments obtained for pre-existing diseases. If you prove that you were insured in the earlier years it is sufficient.

Call me if not clear - 09448120373 - Dr. Raviprakash.