Guaranteed renewal means that when the insurance expires and the applicant applies to the insurance company, the insurance company must continue to underwrite the product according to the agreed rate and original terms. Whether the product is discontinued or not, and whether the physical condition or age of the insured changes, the insurance company must renew the product, rather than guarantee the renewal. The insurance company may stop selling and adjust the premium rate, but the insured's physical condition changes or he is too old, so the insurance company feels that it has to bear more risks.
Most health insurance in the market is a promise renewal, which is different from the guarantee renewal. Commitment to renewal also faces the risk of failure in renewal. However, in order to increase their sales, many insurance companies will interpret their products as guarantee renewal. When purchasing insurance, consumers must carefully read the insurance clauses, check the guarantee period and renewal clauses in the insurance contract, and carefully understand the insurance products to avoid being misled by sales, which will eventually lead to claims disputes.
Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.