I work for an insurance company so can shed some light here as this article is written by someone that clearly doesn't understand how the business model works.

Fundamentally every insurance company is governed by 3 ratios, loss ratio (what percentage of premium is paid to make the buyer of the insurance whole), expense ratio (cost of doing business, paying staff, keeping office lights on, paying vendors) and combined ratio (both of these combined). These are true for any insurance company which writes premium using their own capital, whether its health insurance, life insurance, property insurance, SMB insurance.

The thing this article is missing here is that the "pass through" costs are costs incurred by UHG directly, they are the ones paying the bills. How is this pass through, it's not being passed to the consumer, the only thing I pay is my deductible and retention which is at most a couple of thousand dollars, these are true costs borne by UHG. So in practice if I pay 100 bucks every paycheck, UHG is taking in 2600 bucks worth of premium, using average industry loss ratios which are say 60%, UHG is paying directly 1,560 bucks to care providers for my own care. I'm not paying that, what I pay is a deductible which is treated entirely separately.

I am the biggest insurance skeptic in the world because I think the business model is awful, a business's return on capital averages at 5-10% a year which is truly an awful return for how much capital is required. Insurance companies will make between 0 and 10% of underwriting profit a year (the pure profit from insurance premium minus total expenses) and they usually operate a very large investment vehicle invested typically 70% into bonds/gilts. That being said, this doctor's view of how insurance accounting works by comparing it to a biopharma or a trading brokerage firm is immensely disingenuous.