Depends on the doctor and/ or the hospital you are seeing. In general doctors prefer to see patinets with health insurance plans that are in network with their contracted carriers. If you have an HMO plan and all your providers accept the plan, that is a perfect case scenario. The good news, you are saving on the monthly premiums. A PPO plan however also have a network of providers participating and others are not. So even on a PPO plan you still need to make sure that your doctors are in network, otherwise you may have a higher coinsurance and deductible.
PPO health insurance plans offer freedom to choose a provider whereas HMO plans have predetermined managed network of healthcare providers and medical facilities. In addition on an HMO plan (most plans) you have to have a PCP (primary care physician) selected at the time of the enrollment in the health insurance plan, otherwise the insurance company may randomly assign a PCP. HMO (health maintenance organizations) health insurance plans tend to have lower premiums and smaller network of providers. Generally, HMO health insurance plans may not be used out of the state (unless in case of emergency) and need a referral before seeing a specialist.