Network-based plans may be either closed or open. With a closed network, enrollees' expenses are generally only covered when they go to network providers. Only limited services are covered outside the network—typically only emergency and out-of-area care. Most traditional HMOs were closed network plans. Open network plans provide some coverage when an enrollee uses non-network provider, generally at a lower benefit level to encourage the use of network providers. Most preferred provider organization plans are open-network (those that are not are often described as exclusive provider organizations, or EPOs), as are point of service (POS) plans.
The UK's National Health Service (NHS) is a publicly funded healthcare system that provides coverage to everyone normally resident in the UK. It is not strictly an insurance system because (a) there are no premiums collected, (b) costs are not charged at the patient level and (c) costs are not pre-paid from a pool. However, it does achieve the main aim of insurance which is to spread financial risk arising from ill-health. The costs of running the NHS (est. £104 billion in 2007-8)[39] are met directly from general taxation. The NHS provides the majority of health care in the UK, including primary care, in-patient care, long-term health care, ophthalmology, and dentistry.

Private health insurance may be purchased on a group basis (e.g., by a firm to cover its employees) or purchased by individual consumers. Most Americans with private health insurance receive it through an employer-sponsored program. According to the United States Census Bureau, some 60% of Americans are covered through an employer, while about 9% purchase health insurance directly.[53] Private insurance was billed for 12.2 million inpatient hospital stays in 2011, incurring approximately 29% ($112.5 billion) of the total aggregate inpatient hospital costs in the United States.[12]
Having health insurance is important for several reasons. Uninsured people receive less medical care and less timely care, they have worse health outcomes, and lack of insurance is a fiscal burden for them and their families. Moreover, the benefits of expanding coverage outweigh the costs for added services. Safety-net care from hospitals and clinics improves access to care but does not fully substitute for health insurance. These findings are supported by much research, although some cautions are appropriate in using these results.

All U.S. citizens living in the United States are subject to the individual shared responsibility provision as are all permanent residents and all foreign nationals who are in the United States long enough during a calendar year to qualify as resident aliens for tax purposes. This category includes nonresident aliens who meet certain presence requirements and elect to be treated as resident aliens. For more information see Pub. 519. More: Shared Responsibility from the IRS (See Question 11)
You may be able to get extra help to pay for your prescription drug premiums and costs. To see if you qualify for getting extra help, call: 1-800-MEDICARE (800-633-4227). TTY or TDD users should call 877-486-2048, 24 hours a day/7 days a week; The Social Security Office at 800-772-1213 between 7 a.m. and 7 p.m., Monday through Friday. TTY or TDD users should call, 800-325-0778; or Your State Medical Assistance (Medicaid) Office.