In some locations there is full health-care coverage but it doesn’t include dental care. In other locations there is no automatic health-coverage at all; in some there are vouchers to pay for insurance.
There are also large groups of ‘ex-pats’ residing abroad. For example, many US citizens living in neighboring countries ( ‘close-by’ but hundreds of miles, or a few thousand miles, from home) because life there is much cheaper, but the standard of medical care they prefer may not be simply available.
People in the same location, or people in various locations but with the same medical needs, can collaborate to contract with providers, perhaps even in ways that make them eligible for some insurance (or Medicare) reimbursement. Similarly, individual providers or companies can compete to arrange care for people in this category.
Also: people who are nearing retirement can collaborate to form communities abroad, making sure also that their health-related needs are adequately taken care of.
Local municipalities which are eager to host ex-pats can arrange for land to be made available, or to perform oversight of the project so that all proceeds as planned and local corruption and criminal issues do not interfere, and can also arrange integration with the local medical facilities to provide basic services as well as clinic-space and dental facilities for visiting medical & dental specialists, physical therapists etc, who have contracted with the ex-pats.