I volunteer as a teaching assistant in a public high school, and was talking to a substitute teacher recently. She works 90 days a year as a sub, because the teachers' contract with the district stipulates that 90 days is the minimum to maintain benefits such as health insurance.
That sounded like a pretty good deal to me. School started in September and by Thanksgiving she was almost at her target. The rest of the year, she travels. Average pay for a sub here is $25/hour, which means she's basically working for free: 90 days gets around $14k. But it's a fairly low-stress job.
Losing employer-sponsored health insurance is one of the major expenses between retiring early and Medicare. Even my sponsored health insurance costs me almost $500/month, and my deductible is $5k/year. And by today's standards, that's a generous plan.
What jobs have people researched that provide health insurance for the minimum number of days/hours worked?