PPO and HMO are symptoms of our terrible US health system. They are focused on cost control, not positive outcomes. Basically they are middle-men between doctors and their patients. They get to approve/deny care choices. They get to decide, ex post facto, whether or not they will pay for healthcare services, medicines, etc.

Here in the US, you can get surprise medical bills greater than $10k USD, due to these organizations saying "nope, not gonna pay for that."

While in some cases, homeotherapy, and similar, this is justified ... in many/most cases, it really isn't. HMO/PPO etc are all about reducing cost of the care, with these organizations funding themselves from driving down the cost of the the service.

Doctors have to hire people to handle dealing with the insurance companies (HMO/PPO/etc.) Its expensive and time consuming to deal with them.

PPO is preferred provider organization. You can see specialists easier and have more latitude to pick your providers, assuming they are in the network. ENT is ear nose and throat, also called otolaryngologists, who do sinuses and hearing and throat cancers and that sort of thing. Usually they are surgeons. HMO is a health maintenance organization which is usually cheaper and offers less choice for the patients but also pays for preventative services more but can be bureaucratic if you have a rarer problem. I use Kaiser because I believe in the focus on data driven treatment and prevention, and haven’t had rare diseases yet. We have used them for vasectomy, breast cancer, cornea replacement, and trans transitioning all fine effect. I have a friend whose wife had some standard type of valve replacement and also had a good experience, tho my friend was heavily involved in meeting with the surgeons and consulting on the operation planning. Most people have common problems, so it works well as a first level, I think.

Edit: Kaiser is non profit. There are HMOs which exist primarily as cost control organizations, not primarily committed to health care, so experienced vary

ENT - ear nose and throat

HMO - health maintenance organization. It's a type of insurance where you have to get referrals from someone you designate as your primary care provider.

PPO - preferred provider organization. Another type of insurance where some providers are "preferred providers" who partner with the insurance company to offer reduced rates. You don't need a referral to see a specialist, but many specialists won't see you without a referral anyway.

I have no idea what a "PPO doctor" is, I've never heard of a doctor that only accepts PPOs, that's ridiculous. I guess if a referral is required then the nebulous "they" won't refer you to the "good" ones if you have an HMO?? Except, in practice, you end up at the same handful of providers in your area no matter your insurance. I've had both HMOs and PPOs throughout the years, same shitty doctors on both.

https://m.youtube.com/watch?v=-wpHszfnJns&t=1627s

“A terrible guide to the terrible terminology of U.S. Health Insurance” by Brian David Gilbert

PPO is insurance that you pay more for but you can pick the doctors and services. HMO is insurance where the insurance company picks the doctors and services. ENT is a specialist doctor.