Covered California Bronze BCBS HDHP. $358/mo premium at 36 y/o. In network, $7K deductible and $7K out-of-pocket max. Out-of-network $14K deductible and $20K out-of-pocket max.
Those deductibles and out-of-pocket maxima stack, so if you use both in-network and out-of-network it could be $21K deductible and $27K out-of-pocket max.
Like any insurance, I only buy coverage to handle a loss that I couldn't. $27K would sting, but OTOH in a typical year I don't have to fight for reimbursements because I'm not entitled to any :D.