When Heather Hirsch graduated from Ohio University six years ago and got her first job in Chicago, she faced what most young professionals see in the first week of work: What health-insurance plan should I select?

“We did have somebody come in and explain the plans, at a really high level, for people who didn’t know anything about them,” she says. “They’d say you can choose this deductible or that deductible or that one—but guess what? We don’t know what a deductible is.”

Now, Hirsch, 28, is the Southern Ohio marketing manager for Humana Inc., one of the five biggest health-insurance companies in the United States, and she has a much better handle on how medical plans operate.

The Affordable Care Act, also known as Obamacare, has changed the landscape of health insurance. While many companies continue to offer their group-health plans, many have changed the plans available to shift more of the costs onto employees.

To start, your company will provide a Statement of Benefits and Coverage, which will list what’s available for each plan offered. The plans will list coverage for services such as doctor visits, hospitalization, emergency services and prescription drugs. As part of the plan, there’s a network of providers, so you should check to make sure that your preferred doctors are in the network you choose. Out-of-network care often isn’t covered in the same way that in-network care is covered and can be costly.

The plans also will detail your costs. There generally is a payroll deduction for an employee’s share of the health-care insurance premium (with the company picking up the rest). Usually, the more you pay upfront, the less you pay when you need care. On the reverse side of that, if you are healthy and you choose a plan that is less expensive, you will pay more if you have a need for care.

Some key terms:

Copays: Your share of doctor visits, prescriptions, etc. (It could be, say, $35 for an office visit, with insurance picking up the rest).

Coinsurance: An amount that you share with an insurance company. You could have a plan that pays 80 percent for a procedure, and you pay 20 percent.

Deductible: The amount that you are required to pay before insurance kicks in. If you are responsible for the first $2,000 and incur costs of $5,000; you would pay the $2,000, and insurance would pay $3,000. Often, the plan will pay for regular checkups before a deductible kicks in; the idea is that you are taking care of yourself. “Weigh the risks if you want to get a high-deductible plan,” Hirsch says.

Health-care flexible spending account: An account that holds money deducted each paycheck to pay for things not covered by insurance—for example, copays, coinsurance and some over-the-counter medicines and devices. The advantage is that you are paying with pretax dollars.

Out-of-pocket limits: The maximum amount that you will pay annually for health care under the plan. In general, the higher the limit, the less costly the plan, but keep in mind that you could be responsible for a large bill. If you have health conditions or go to the hospital often, consider this, Hirsch says.

What do you do if your company doesn’t offer a plan? The next enrollment period for Obamacare began Nov. 15 through the Health Insurance Marketplace, which guarantees coverage and offers a number of plans, labeled Bronze, Silver, Gold and Platinum.