Just over a week remains until consumers will be able to shop for health plans through insurance exchanges, online tools that will give Americans — including millions who are now uninsured — access to expanded coverage and new ways to determine which health plans best fit their needs. In order to prepare consumers for this unprecedented change, U.S. News held a Twitter chat with experts from the Department of Health and Human Services (HHS), the government agency overseeing the implementation of exchanges, and the National Patient Advocate Foundation (NPAF), a nonprofit that helps patients obtain financially suitable health care. Experts discussed the basics of exchanges, how to prepare for enrollment, what costs to factor in, and what benefits to expect. The chat's 300 participants sent 1,142 tweets during the course of the discussion.

The Basics

Open enrollment begins Oct. 1, 2013, and extends until March 31, 2014. Health coverage can start as early as Jan. 1, 2014. Individuals and families who are citizens or legal residents will be able to use the marketplaces, as will small businesses. "Did you know? Those with student visas may be eligible for marketplace plans," NPAF noted. Medicare recipients will not need to use the exchanges.

How should consumers prepare for enrolling in exchanges?

People signing up for health insurance through exchanges will need information about their household income, personal identification information such as social security numbers and policy numbers for any current coverage. They also need to have information about any dependents, including social security numbers and income information. Those planning to sign up through exchanges also should try to assess their current and future medical needs in order to choose the right plan, tweeted NPAF. Consider whether you have any chronic illnesses that require monitoring and treatment, or whether you have children with allergies. Do you have a history of diabetes in your family? Knowing how much medical care you're likely to need over the next year, will help you choose the plan that best meets your needs at an affordable cost. To find out more, sign up for text or email updates through HealthCare.gov, the agency said.

What costs should people be ready for?

The exchanges will allow consumers to compare monthly premiums, annual deductibles, coinsurance and copays to evaluate out-of-pocket costs for each plan. HHS tweeted that 90 percent of those who are currently uninsured can qualify for discounted or free insurance. The health insurance exchanges are designed to provide that information automatically, when consumers fill out the online application forms. Help may come in different guises: lower premiums, tax credits or financial assistance. The marketplaces will also allow people to enroll into Medicaid or the Children's Health Insurance Program (CHIP).

People who do not sign up for a health insurance plan by March 31 will pay a tax penalty for each month that they are uninsured, and the penalty will increase every year until 2016. The fee in 2014 is 1 percent of a person's yearly income or $95 per person, whichever is higher, HHS said. But, the agency pointed out, those who do not sign up face even more significant costs. "They also have to pay the entire cost of all their medical care and won't be protected from very high medical bills."

What benefits can individuals and families expect?

UPMC Health Plan in Pittsburgh tweeted that each plan covers at least 10 "Essential Health Benefits," including preventive care, emergency treatment, hospitalization and prescriptions. Preventive services include annual wellness visits, vaccinations and flu shots. Women can get free mammograms, well-woman visits and contraception, tweeted HHS's Office of Women's Health. They will not be denied coverage or charged more due to pre-existing conditions, such as cancer or being pregnant. Dental and vision plans will be offered to children, but adults who want the coverage must purchase it separately.