Another health care plan available in US and similar to HMO is known as preferred provider organizations. You will have to pay a premium amount every month which is fixed to the insurer. The network of health care and the health insurance company will provide you with the medical benefits in return for this.

Under PPO you will not have a primary health care physician as you have in HMO. So you will not have to go for a referral when you want to consult a specialist. In case of out of network services, you will have to go for a higher co-payment.