Health insurance terms, plainly

Premium: The amount you pay each month to keep your health plan, whether or not you use any care that month. It is one cost among several: the deductible, copays and coinsurance come on top when you get care.

Deductible: What you pay for covered care each year before your plan starts to pay its share. Many plans cover some services, such as preventive care, before you reach it, and family plans often have both a per-person and a family deductible.

Copay (copayment): A fixed amount you pay for a covered service, such as a doctor visit, usually after you have met your deductible. Your plan summary lists the copay for each kind of visit.

Coinsurance: Your share of the cost of a covered service, shown as a percentage rather than a fixed amount. If a hospital stay follows a farm injury, coinsurance is usually how your share of that bill is worked out.

Out-of-pocket maximum: The most you pay for covered, in-network care in a plan year. Once your deductible, copays and coinsurance reach it, the plan pays the full cost of covered benefits for the rest of the year. Premiums and out-of-network care do not count toward it.

• healthcare.gov: premium
• healthcare.gov: deductible
• healthcare.gov: coinsurance
• healthcare.gov: out-of-pocket maximum

Network: The doctors, hospitals and other providers your plan has a contract with. In rural areas the nearest hospital may or may not be in a given plan's network, so check it by name.

In-network: Care from a provider inside your plan's network. It usually costs you less than the same care outside the network.

Out-of-network: Care from a provider your plan has no contract with. You usually pay more, some plan types do not cover it at all except in an emergency, and it does not count toward your out-of-pocket maximum.

Formulary: The list of prescription drugs a plan covers, also called a drug list. Check each regular medicine on next year's list before you renew, since lists can change.

• healthcare.gov: network
• healthcare.gov: out-of-network
• healthcare.gov: formulary

Open Enrollment: The yearly window when you can enroll in or change a Marketplace plan. healthcare.gov lists it as November 1 to January 15. Our Open Enrollment guide has the full dates.

Special Enrollment Period: A time outside Open Enrollment when you can sign up after certain life changes, such as losing other coverage, moving, getting married or having a baby. healthcare.gov says you usually have 60 days before or after the change.

Renewal notice: The letters that tell you what happens to your plan next year. healthcare.gov says Marketplace customers should get two by November 1, one from the insurance company and one from the Marketplace. Our guide reads one line by line.

• Open Enrollment for farm households
• healthcare.gov: special enrollment period
• Your renewal notice, read part by part

Marketplace: The service where you shop for and enroll in individual and family health plans, also called the exchange. In most states it runs at healthcare.gov; some states run their own Marketplace on a different website.

Premium tax credit: A tax credit that can lower your monthly Marketplace premium, based on your household and the income you estimate on your application. healthcare.gov says the Marketplace is the only place to get it.

Cost-sharing reduction: A discount that lowers what you pay for deductibles, copays and coinsurance, often called "extra savings" on the Marketplace. healthcare.gov says you get it only on a Silver plan, if your application shows you qualify.

Metal levels: The four categories Marketplace plans are sorted into: Bronze, Silver, Gold and Platinum. healthcare.gov says the categories have nothing to do with the quality of care; they reflect how costs are split between you and the plan.

Private plan: On this site, a health plan bought outside the Marketplace, directly from an insurance company or through a licensed advisor. A premium tax credit cannot be used on it, because that credit is only available through the Marketplace.

• healthcare.gov: marketplace
• healthcare.gov: premium tax credit
• healthcare.gov: cost-sharing reduction
• healthcare.gov: metal levels
• Marketplace or private plans

HSA (Health Savings Account): A savings account for qualified medical expenses, funded with pre-tax money. You can contribute to one only if you have an HSA-eligible plan. The IRS sets the rules, in Publication 969.

HSA-eligible plan: A plan with a higher deductible that can be paired with an HSA, also called a high deductible health plan. The monthly premium is usually lower, and you pay more of your care yourself before the plan starts to pay.

• healthcare.gov: HSA
• healthcare.gov: HSA-eligible plan

If a subsidized Marketplace plan still fits your household, healthcare.gov is usually the simpler route, and its own glossary covers these terms too. This page is written for farm households paying most or all of the premium themselves.