What type of accident and health insurance policy cannot be changed by the insurer up to a stated age?

The correct answer is noncancelable. A noncancelable policy is designed to offer the policyholder a high level of security because it guarantees that as long as premiums are paid on time, the insurer cannot change the policy's terms, including the premium amount, or cancel the policy up until the policyholder reaches a specified age, typically around 65. This provides a significant advantage to individuals who may face health issues later in life, as they can maintain their coverage without facing potential changes that could be unfavorable.

In contrast, guaranteed renewable policies allow for renewal but permit the insurer to increase premiums based on the overall risk factors for the pool of insured individuals, not on the individual’s health status. Cancelable policies can be terminated by the insurer with advance notice, meaning that they can be changed depending on the insurer's discretion. Optional renewable policies provide the insurer with the option to renew but do not compel them to do so, allowing for potential policy changes as well. Thus, noncancelable policies are unique in providing durable coverage with no alterations by the insurer until the predetermined age, making them a vital choice for those seeking long-term stability in their health insurance.