Hot-button Obamacare goes online Tuesday

But even if the government shuts down in a dispute over the law’s funding, the health care law will continue to be implemented because much of the funding is mandatory and not part of Congress’ annual discretionary appropriations. Funding could be stopped only if the law were repealed.

Run by either the federal government or the states themselves, the marketplaces will allow individuals, families and small businesses to enroll in health plans that the law dictates must cover a wide range of essential benefits and can’t deny coverage because of current or past health problems.

Marketplace plans also will limit older people from being charged more than three times the amount of young adults, ban spending limits for medical expenses and prohibit rate differences based on gender, occupation and medical claims history.

People who earn up to four times the federal poverty level — $46,000 for an individual this year — can get federal subsidies, or “tax credits,” to help buy marketplace coverage. Many of them will get additional subsidies that limit such out-of-pocket costs as co-payments and deductibles.

The health care law requires most Americans to have health insurance beginning in 2014 or face a fine, which will be levied when they file their income taxes next year.

Recent computer problems suggest the marketplace debuts may not go smoothly. Small-business enrollments in 36 states where the federal government either will run or jointly operate the marketplaces have been postponed until November due to technical glitches. Maryland, Oregon and the District of Columbia have delayed key marketplace functions until computer problems are fixed.

Tuesday’s marketplace debut isn’t likely to spawn a rush of eager buyers, because people have until Dec.15 to buy coverage that begins on Jan. 1. During that time, many people will interact with the marketplace more than a dozen times before they make purchases, said Heather Howard, the state network program director at the Robert Wood Johnson Foundation, a public health philanthropy.

Most states probably will see spikes in marketplace activity just before the Dec. 15 deadline for enrolling by Jan. 1, and just before the 2014 open enrollment period ends March 31, Howard said. An estimated 7 million people are expected to have enrolled by then.

Buying coverage before March 31 will fulfill the mandate that individuals have health insurance by 2014.

In addition to online enrollment, marketplaces will have telephone call centers to help people sign up, as well as community enrollment workers, or “navigators,” who have been trained to assist with enrollment.