POS vs. HMO

POS plans require that you to go to a primary care provider first to get a referral to a specialist, just like a health maintenance organization (HMO) plan. POS plans allow for coverage outside the plan or network, usually at a reduced percentage, while care is strictly limited to the provider network in an HMO.

POS vs. PPO

PPOs provide more freedom than a POS to see any provider within the organization without referrals. Both plans offer reduced fees for limiting the number of providers in their respective networks.

Advantages

A POS provides reduced costs without ridged limitations for who you can see and still receive some coverage.

Disadvantages

You have to coordinate your health care through a primary care provider, which can actually be a benefit if you find the right doctor.

Other Considerations

If you are selecting between a POS, HMO and/or PPO, take into consideration all upfront costs, co-pays per visit and total potential deductibles to compare plans. Also, if you tend to be healthy or to not go to the doctor all that much, you might save money by reducing your freedom of choice in exchange for lower monthly fees.

Source:

Insurance Information Institute: What are my health insurance choices?