In 1948 Costa Rica abolished its army and put some of the money it saved into developing a network of primary health posts all over the central American country.
Six decades later the country has a rapidly growing elderly population who now get free health care.
But the country has a financial problem in that it can no longer afford its health service.
Claudia Hammond travels to the capital, San Jose, where she meets the researchers who are finding out about the health needs of the over 60s and the doctors who are caring for these people, in the community and in hospitals.
She also visits one of the few old peoples' homes in the country and talks to the residents about why they think Costa Ricans live so long.