[ethbr1]

It's both.

Medical fraud is like retail stock shrinkage or fraudulent credit card charges -- no one on the customer side is aware of it, because it's handled on the other side and baked into pricing.

But there are substantial amounts of both straight fraud and too aggressively up-coding / over-billing.

The meta problem is that the because of the nature of the industry (legitimate volume dwarfs fraud), it's more financially impactful to pull levers that impact legitimate volume (read: prior auth requirements).

The anti-fraud systems are also pretty robust. As you'd imagine, insurers have been dealing with this for more than a few decades by now.