What health insurance actually does

Health insurance is a contract between you and an insurance company: you pay a monthly fee (called a premium), and the company agrees to pay part of your medical bills when you need care. You do not pay the full cost of a doctor visit or hospital stay yourself — the insurance company covers some of it, and you cover the rest through deductibles (the amount you pay before insurance kicks in), copays (a fixed fee per visit), and coinsurance (a percentage of the bill you split with the insurer).

The insurance company does not pay for everything. Each plan has a list of covered services — which doctors you can see, which medications are covered, which procedures require advance permission. Plans also have an annual limit on what you pay out of pocket; once you hit that limit, the insurance company covers 100 percent of additional costs for the rest of that year.

Health insurance in the United States comes from four main sources: your employer, the government (Medicare for people 65 and older, Medicaid for low-income people, or the Veterans Health Administration), the individual market (where you buy directly), or a combination. Where you get insurance from determines which plans you can choose and what they cost.

Key Takeaways

  • Your monthly premium, deductible, copays, and coinsurance all affect your total cost — comparing only the premium misses half the picture.
  • In-network providers (doctors and hospitals the insurance company has a contract with) cost less than out-of-network ones, so check whether your current doctor is in the plan's network before you enroll.
  • Employer plans, government programs, and individual market plans have different rules about what they cover and how much you pay, so the cheapest option depends on your income and health needs.
  • Plans are required to cover preventive care (annual checkups, screenings, vaccines) at no cost to you, but they vary widely on specialist visits, mental health care, and prescription drugs.
  • If you lose employer coverage or have a major life change, you may have a limited window to enroll in a new plan outside the standard open enrollment period.

The real cost: premium, deductible, and out-of-pocket limits

A plan with a low monthly premium often has a high deductible — you pay less each month but more when you actually need care. A plan with a high premium often has a low deductible and lower copays. Neither is automatically better; it depends on how often you see a doctor and what you expect to spend.

Example: Plan A costs $150 a month with a $2,000 deductible. Plan B costs $300 a month with a $500 deductible. If you rarely go to the doctor, Plan A saves you money overall. If you have a chronic condition and see specialists regularly, Plan B probably costs less in total because you hit the deductible faster and then pay only copays.

Every plan also has an annual out-of-pocket maximum — the most you will pay in deductibles, copays, and coinsurance combined in one year. Once you reach it, the insurance company pays 100 percent of covered services for the rest of that year. Out-of-pocket maximums vary by plan and by income; for 2024, federal limits range from roughly $1,600 to $9,200 for individual coverage, depending on the plan type.

Network, in-network, and what happens if you go out-of-network

Every insurance plan has a network — a list of doctors, hospitals, and other providers that have a contract with the insurance company. When you see an in-network provider, you pay the negotiated rate (your copay or coinsurance). When you see an out-of-network provider, you pay a much higher percentage of the bill, and it may not count toward your deductible or out-of-pocket maximum.

Before you choose a plan, check whether your current doctor, specialist, or preferred hospital is in the network. You can usually find this on the insurance company's website by searching for providers by name or location. If your doctor is not in the network and you want to keep seeing them, you will either need to pay more or switch plans.

Emergency care is an exception: if you go to an out-of-network emergency room, the insurance company will usually cover it at the in-network rate, even though you did not choose the hospital. Non-emergency urgent care (like a walk-in clinic) may not have the same protection, so ask before you go.

Employer plans versus individual plans versus government programs

If your employer offers health insurance, that is usually the cheapest option because your employer pays part of the premium. You choose from the plans your employer offers, and enrollment happens once a year (or when you are first hired). The trade-off: you have fewer choices than the individual market, and if you leave the job, you lose the coverage.

If you buy insurance on your own through the individual market, you have more plan options but you pay the full premium yourself. You can enroll during the annual open enrollment period (usually November 15 to January 15) or if you have a may have access to life event — losing a job, getting married, having a child, moving to a new state. Outside those windows, you cannot enroll unless you have a special circumstance.

Government programs cover people who meet specific criteria. Medicare covers people 65 and older and some younger people with disabilities. Medicaid covers low-income individuals and families; income limits and covered services vary by state. TRICARE covers active-duty military, retirees, and their families. Veterans Health Administration covers may be able to access veterans. These programs have different enrollment rules, covered services, and costs.

What is actually covered: preventive care, prescriptions, and mental health

All health insurance plans are required to cover preventive services at no cost to you: annual checkups, blood pressure screening, cancer screenings, vaccines, and counseling for certain conditions. You do not pay a copay or deductible for these services if you use an in-network provider.

Beyond preventive care, coverage varies. Most plans cover doctor visits, hospital stays, and emergency care, but the copay or coinsurance you pay depends on the plan. Specialist visits (dermatologist, cardiologist, orthopedist) often have higher copays than primary care. Mental health visits and substance use treatment are required to be covered at the same level as physical health care, but some plans still charge higher copays or limit the number of visits.

Prescription drug coverage also varies. Plans have a formulary — a list of covered medications. Some drugs are covered fully, others require you to pay a percentage, and some are not covered at all. If your doctor prescribes a medication that is not on the formulary, you can ask the insurance company for an exception, but approval is not may provide. Generic medications are usually cheaper than brand-name drugs.

How to compare plans side by side

When you are choosing between plans, create a straightforward spreadsheet with these columns: monthly premium, annual deductible, copay for a primary care visit, copay for a specialist visit, copay for an emergency room visit, coinsurance percentage (the percentage you pay after the deductible), and annual out-of-pocket maximum. Add a row for each plan you are considering.

Then estimate your own use: How many times do you see your primary care doctor in a year? Do you see any specialists? Do you take prescription medications? Do you expect any surgeries or hospital stays? Plug those numbers into each plan and calculate your total expected cost (premiums plus estimated out-of-pocket costs). The plan with the lowest total is usually the best choice for your situation.

Do not forget to check the network. If your doctor is out-of-network in a plan, add the higher out-of-network cost to your calculation. If the plan does not cover a medication you take, ask the insurance company whether a covered alternative exists or whether you can get an exception.

What happens when you lose coverage or have a major life change

If you lose health insurance through your job, you have the right to continue your employer's coverage for up to 18 months through a program called COBRA — but you pay the full premium yourself (usually 102 percent of what the employer and employee paid combined), so it is expensive. You also have 60 days to enroll in individual market coverage or a government program without waiting for open enrollment.

may have access to life events that let you enroll outside the standard open enrollment period include losing a job, getting married, having a child, adopting a child, moving to a new state, or losing other coverage. You usually have 30 to 60 days from the event to enroll. If you miss the important date, you will have to wait until the next open enrollment period.

If you cannot afford insurance, you may be able to get help through Medicaid, the Children's Health Insurance Program (CHIP), or subsidies on individual market plans. Income limits and available programs vary by state and family size.

Frequently Asked Questions

What is the difference between a copay and coinsurance?

A copay is a fixed dollar amount you pay for a service — for example, $25 for a doctor visit. Coinsurance is a percentage of the bill you pay after you have met your deductible — for example, you pay 20 percent and the insurance company pays 80 percent. Some plans use copays, some use coinsurance, and some use both.

Can I see a doctor without meeting my deductible first?

Preventive care (checkups, screenings, vaccines) does not require you to meet your deductible. For other visits, you pay the full cost until you reach your deductible, then you pay only your copay or coinsurance. Some plans waive the deductible for urgent care or emergency room visits.

What happens if my doctor leaves the network?

If your in-network doctor leaves the plan, the insurance company usually notifies you and gives you time to find a new in-network provider or request an exception to keep seeing your current doctor at the in-network rate. Contact your insurance company as soon as you learn your doctor is leaving.

Do I have to enroll during open enrollment?

If you have employer coverage or are already enrolled in a plan, you can usually make changes during the annual open enrollment period. If you have a may have access to life event (job loss, marriage, birth, move), you can enroll outside open enrollment. If you do not have coverage and miss open enrollment, you cannot enroll until the next open enrollment period unless you have a may have access to event.

What if I cannot afford my insurance premium?

If you buy insurance on the individual market, you may be able to get a tax credit that lowers your monthly premium based on your income. If you have very low income, you may be able to enroll in Medicaid. Contact your state's health insurance marketplace or a local community health center to learn what programs you may be able to use.