Consider Medicaid, school health insurance plans, employer plan, healthcare.gov
If they can get on Medicaid, that may be best, especially as students. It exists, so take advantage of it if available. They may also get a good effective rate through Obamacare plans because of cost subsidies depending on their income. It also depends on their medical needs. Probably those two options are best, though, if they don't have full-time jobs.
I have no experience with married students on parents' health insurance plans, so if that is still possible (as some here seem to say), then maybe that is also an option.