I’ve posted this in another thread before, on the high costs of insulin, but if you replace ”pharma company” with healthcare provider and “medication” healthcare services, the same will largely hold true:

Insurance companies in the US have enormous leverage over just about every other party involved in healthcare: the patients, the providers, and the pharmaceutical manufacturers. This is even more true for medications like insulin, where there isn’t much difference in efficacy between brands. In a normal market, these companies would try to compete on price. But for insulin, price continues to rise. This is because insurance companies, and their negotiators, Pharmacy Benefit Managers (aka PBMs) have a vested interest in prices rising.
PBMs make their money by negotiating prices with pharma companies to secure discounted prices for insurers, and in doing so, create the insurers’ “formularies”, which are basically the list of all the medications an insurer will cover, the prices they will pay, and the conditions that must be met. PBMs get a cut of the discount they negotiate with the pharma company. If drug A has a list price of $200, and they negotiate it down to $150 for their insurance clients, they take home x% of all the savings that are made at $50 a pop.

This creates a perverse incentive however: a PBM stands to make more from a drug that costs $300 and is negotiated down to $150 than a drug that is $200 that is negotiated down to $150, even if everything else is the same. That means you are more likely to get better insurance coverage for your drug by starting high and giving deep discounts. And for drugs like insulin, where similarities between products are so small that the only place you can compete is price, how well you are covered by insurers compared to your competitors will make or break your business.

Insurance companies themselves also love drugs with high costs that are then discounted deeply, because when they charge a patient coinsurance, it’s based on the list price, and not the price the insurer is paying. So even though they’ve negotiated the price of insulin down by over 50% with the pharma company, they are still going to charge you y% based on the full price. So if they continue to get insulin from manufacturers for $Y per unit every year, they continue to charge you 20% of a cost that continues to rise further and further away from $Y, meaning they are actually paying less and less as prices rise. They will claim to be using the reduced costs to lower premiums, but if reduced costs are only the result of increased costs for the sick, then all we’ve done is create an insurance system where the sick are subsidizing the healthy, which is entirely backwards.
So now we have a system where manufacturers raise prices year after year, only to also give ever increasing discounts to insurance companies and PBMs, in hopes that it actually increases the number of patients who can afford their products (i.e. those with decent insurance). But those left holding the bag are the individuals without insurance or those with high deductible plans (which are becoming increasingly common).

It’s also important to note exactly how much power these middlemen have. It’s a common narrative that Big Pharma is able to get away with bad practices because of their power. But in reality, only a single pharmaceutical company is in the Fortune 50, and none of the insulin makers are. In contrast, 80% of the PBM market is controlled by 3 companies, 2 of which are Fortune 50, and the third is a subsidiary of United Health, which is an insurer and is also Fortune 50. In fact, 10 of the Fortune 50 companies are middlemen (insurers, PBMs, or drug distributors) in the healthcare industry.

Basically, discounting and rebates have ironically been a big driver behind increasing healthcare costs. They serve primarily to reduce insurers costs but they don’t pass those benefits to consumers, and have actually created a system that rewards high-cost healthcare.