What is the term for when a doctor inflates medical bills and bills both health and workers' compensation insurance?

The correct term for the scenario described is indeed "Medical Mill." This term refers to a practice where certain medical providers generate unnecessary medical treatments or inflate the costs of services, often to maximize insurance payouts. In this case, the action of billing both health insurance and workers' compensation insurance for inflated medical services aligns with the description of a Medical Mill, which can exploit the system and lead to significant financial losses for insurers.

While "Medical Build-Up" may seem like a plausible term, it does not specifically denote the fraudulent activities surrounding the inflating of bills and double-billing practices. Similarly, "Moral Hazard" refers to the risk that individuals or entities will take on more risk because they are not bearing the full consequences of that risk, which is a broader concept not limited to medical billing fraud. "Physical Hazard" pertains to tangible elements increasing the risk of a loss, but does not connect to fraudulent billing practices in healthcare. Thus, the distinctions between these terms highlight why "Medical Mill" is the most accurate choice in this context.