Both as a patient and former clinician (OT) I prefer PPOs. You get more control over who you see and when you see them than you do with an HMO and in general PPOs were more reasonable in what they would cover for my patients than HMOs. Like one HMO once cut off my patient's treatment because her stroke was really bad and she had to start t a very basic place and the HMO said if she wasn't able to work on more advanced goals she didn't need therapy (had she been given time she might have gotten to those goals). PPOs can be more expensive.

HMOs are sort of a network of providers and you have to stay in that network for all covered care. You need referrals to see specialists and getting a referral can be hard depending on your regular doctor. PPOs have a lot of providers you can choose from. You can self-refer to specialists and select any hospital/provider in the PPOs network for any admissions/procedures/tests/etc.