In about six weeks, Americans will have a new kind of open enrollment to consider (Wall Street Journal). Starting Oct. 1, people without health insurance can sign up for standardized coverage through new health-insurance marketplaces run either by their state, the federal government or a combination of the two—the centerpiece of the Patient Protection and Affordable Care Act. The coverage will take effect Jan. 1. And people with incomes between 100% and 400% of the federal poverty level—about $23,500 to $94,000 for a family of four—can receive financial help on a sliding scale to offset the costs. These marketplaces, also known as exchanges, will make shopping for health insurance easier than it is today, says Sarah Dash, a research fellow at Georgetown University who has studied the new marketplaces. "Consumers are going to get a much more transparent, apples-to-apples shopping experience." If you have affordable insurance through an employer, or if you have coverage through a government program such as Medicare or Medicaid, you won't be affected by the exchanges. Exchange shoppers will fill out a single insurance application, which will be used to "find out if they can get a tax credit on their premium, help with cost-sharing or if they're eligible for Medicaid in their state," Ms. Dash says. You can calculate your potential premium assistance with an online tool from the Kaiser http://kff.org/interactive/subsidy-calculator/  Family Foundation, which conducts health-care research. This first open-enrollment period will last six months, from Oct. 1, 2013 to March 31, 2014. It generally takes two weeks for a policy to go into effect after enrolling, so you'll need to sign up by Dec. 15 to get coverage starting Jan. 1. Many state call centers already are running. Visit Healthcare.gov or call 1-800-318-2596 for more information.