insurer
Refers to the party that provides insurance coverage, such as an insurance company or a public health insurance body. Often contrasted with 被保険者 (the insured).
See also: 被保険者
The insurer is obligated to pay insurance benefits to the insured.
The insurer for National Health Insurance is the municipality.
被保険者 is the person covered by an insurance policy, while 保険者 is the company or entity that provides the insurance.
Compound of 保険 (insurance) and 者 (person/entity). The term is a straightforward Sino-Japanese formation used in legal and administrative contexts.