pension system; pension scheme
Refers to the overall public or private pension framework, including contributions, benefits, and administration.
Japan's pension system is under strain due to the aging population and low birthrate.
年金 refers to a pension itself (the payments received), while 年金制度 refers to the system or scheme as a whole.
corporate pension plan
Compound of 年金 (pension) and 制度 (system, institution).