Is there any hmo accepting persons more than 60 years old?

i just got married and previously had my parents as dependents on my hmo card. they are both over 60 years old now and I can't find any hmo company to enrol them with since they require for new enrolments that the person is below 60 years old. I understand that this protects them from risks coming from old age but I heard there are some companies that can still extend services to people more than 60. Help please.