Co-insurance: Your share of the medical bill after you’ve paid your annual deductible. Usually shown in a percentage, as in 20 percent paid by you and 80 percent paid by the insurance company.

Co-op: A new kind of nonprofit insurance company run by members for members. Think credit union. Maine has one co-op: Maine Community Health Options, in Lewiston.

Co-pay: That money you plunk down at the receptionist’s window when seeing the doctor.

Deductible: How much you’ll pay each year before the insurance company starts kicking in its share.

Exchange/marketplace: Are you an individual or small business or group? If so, you can buy insurance here. Insurance is sold elsewhere, sure, but this is the only place where individuals can use their federal subsidy to help pay the cost. It’s also the only place where small-business owners can get a tax break for buying insurance for their employees. Originally dubbed the “exchange,” it’s now officially the “marketplace.”

Family glitch: When your employer offers affordable coverage for you personally, but pays little or nothing toward health insurance for your family members. In reality, your family’s coverage is unaffordable to you — who has an extra $500 a month when you’re a single mom making $30,000 a year? But the ACA, as written, doesn’t make that distinction. As long as you are offered affordable coverage, no one in your family can get a subsidy to help buy insurance. Advocacy groups have clamored for a fix to the glitch.

Full-time employee: Someone who works 30-plus hours a week and more than 120 days in a year.

Full-time equivalent: Part-time employees whose hours, when added together, equal full time (30-plus hours a week). For example, you and Jacques each work 15 hours a week. Together, you equal one full-time employee. Employers must count full-time equivalents to figure out their ACA requirements and tax credits.

Government-sponsored insurance: Insurance paid by the state or feds. Includes Medicaid and Medicare.

Individual: You. Or you-and-family.

In-network: The doctors and hospitals your insurance company will happily pay for. (It also may pay for out-of network care, but not as much.)

Minimum essential coverage: This is health insurance that meets the ACA’s standards. (It pays for hospitalization, prescription meds, preventative care and emergencies, among other things.) Most plans meet these standards, but vision-only insurance, workers’ compensation insurance and other limited plans do not. So, under the law, you can’t get eye insurance and call yourself insured.

Metal levels: Bronze, silver, gold and platinum. Like medals in the Olympics, these metals help you tell the difference between good, better and best insurance plans. The lowest insurance levels, bronze and silver, cost less each month, but you’ll get fewer benefits and will pay more when you go to the doctor. The highest levels, gold and platinum, cost more each month, but they offer better benefits and you won’t have to pay a lot when you see the doctor.

Narrow network: Want to see Dr. Smith? Go for it, because your insurance company likes her. Dr. Jones? Nope, sorry (unless you want to pay the bill all by yourself). When an insurance company strictly limits the doctors and hospitals a patient can see in an effort to control costs, it has a narrow network.

Open enrollment: You can buy individual health insurance only during this time unless you have a major life-changing event or you’re a member of a federally recognized tribe or are an Alaska Native shareholder. We’re now in the middle of open enrollment for 2015. It lasts until Feb. 15. (FYI: This is true for insurance bought on or off the exchange/marketplace. If you don’t meet the Feb. 15 deadline and don’t have a qualified life-changing event, you won’t be able to buy insurance for 2015. Open enrollment for 2016 starts next fall.)

Out-of-pocket maximum: The most you’ll have to pay for your health care in a year. Have a $6,000 out-of-pocket maximum with your insurance company? Everything after that is free until the new year rolls around again.

Premium: How much you pay each month for insurance. Think of it as the monthly price tag.

Preventative care: Shots, colonoscopy, depression screening, counseling for alcohol abuse, diet counseling and a bunch of other services designed to keep you healthy or catch an illness before it gets to the crisis point. If you’re insured — whether on your own or through your employer — preventative care is free to you, with no co-pays or co-insurance, even if you haven’t met your annual deductible.

Private insurance: If it’s not government insurance, it’s private. This includes insurance paid by you or your employer. All plans on the exchange/marketplace are private plans, even if you get a subsidy for it.

SHOP: Small Business Health Options Program. It’s where small groups can buy health insurance and get a tax break for it. In Maine, SHOP is the same as the exchange/marketplace. (FYI: Only the employer gets this refundable credit, not employees.)

Small group: Fifty or fewer people. Usually means a small business. The definition will change to 100 or fewer people in 2016.

Subsidy: Money the federal government gives to people who need to buy their own insurance (because an affordable plan isn’t offered through their job) and who earn between 100 percent and 400 percent of the federal poverty level. You can get the subsidy in a tax credit or have it paid directly to the insurance company to lower your monthly bill. If you earn less than 250 percent of the poverty level, you can also get a subsidy to reduce your out-of-pocket expenses. How big of a subsidy? Depends on your salary and the cost of insurance in your area. It’s a sliding scale.