PPO (Preferred Provider Organization)
PPOs are generally less flexible than traditional health insurance plans but more flexible than HMOs. You can see any healthcare provider you want to (including a specialist), but your co-payment will be higher if the physician you choose is not a "preferred provider," that is, a physician the health plan has a contract with.
PPOs will almost always require that you get their approval before entering a hospital. But they are more likely to cover checkups and other preventive medical services than traditional health insurance plans, and most preferred providers will file your claims for you.
POS (Point of Service)
A POS plan is similar to an HMO in that you can see physicians within a network and pay only a small co-payment. But you can also see physicians that aren't in the network and pay a percentage of the charge, after you've met your deductible, as you would with a PPO plan.
There may be restrictions on the services you can receive outside the network with a POS plan. For example, prescription drugs, organ transplants, treatment for infertility, and mental health services may not be included.
EPO (Exclusive Provider Organization)
An EPO is similar to an HMO except that it is regulated by the California Department of Insurance and generally pays physicians and other healthcare providers differently. EPOs will only cover your expenses if you see a physician that is in the EPO's network, unless it is an emergency.
Health Savings Accounts (HSA)
The Health Savings Account (HSA) was created recently by federal legislation. A HSA lets you set aside pre-tax dollars for future medical, retirement, or long-term care premium expenses. You can invest these funds as you wish within a broad range of choices, then use them for qualified expenses. The funds can roll-over from year to year and can be taken with you when you change jobs, which makes an HSA different from other kinds of tax-advantaged savings accounts.
Note: If you are still not sure which type of plan to choose, ask for more information from the health benefits manager at your workplace or a health plan representative. Your physician may also be in a good position to help you compare plans since he or she is familiar with your health and medical history.