How to target the non-quantifiable or tracked demographic audiences

For example, how does one target people with good health insurance? I know targeting by high-income household areas would be a good start and basing keyword structure on high-intent/niche searches that quality by the intent... But what about Facebook ads?

I'm trying to come up with additional ways to effectively target people with private, non-government healthcare.

It's been an uphill battle (although I have decent-ish results on search)