The average health insurance deductible is $4,358 and the average premium is $321 per month.[3] That means that on average US citizens pay $321 per month for (5237-4358) / 12 = $73.25 of expected value. That's a 4X markup over the expected value of insurance.
Health insurance companies might be reporting single digit overheads but they are providing $1 of value for $4 and are inefficient.
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1361028/
[2] https://www.mrmoneymustache.com/2017/11/05/when-your-shitty-...
[3] https://www.cnbc.com/amp/2017/06/23/heres-how-much-the-avera...