At the Silver State Health Insurance Exchange in Carson City, Nev., workers have been counting down the days until Oct. 1 on an office corkboard. Sunday is a big milestone — 100 days to the deadline for opening the online marketplaces that are a linchpin of the federal health law known as Obamacare.

“We certainly will need every one of the days that we have left,” said Jon Hager, executive director of the Nevada exchange. “But I am confident we will be ready to go.”

Nevada is one of 15 states racing to launch their own marketplaces where consumers can compare plans’ prices and benefits, and find out if they are eligible for a federal subsidy or Medicaid. The other states are relying on the federal government. Those marketplaces, also called exchanges, are key to expanding insurance coverage to an estimated 25 million Americans over the next decade.

‘The next hundred days are the sprint to the biggest open-enrollment season we’ve ever seen in this country,” said Ceci Connolly, managing director of PricewaterhouseCoopers’ Health Research Institute. “We know that this will be a real crunch period.”

Opening the marketplaces on time represents the Obama administration’s biggest opportunity to fulfill the law’s promise to extend coverage to uninsured Americans, including those who have been denied coverage in the past because of health conditions. Since the Supreme Court upheld the law last June, though, officials have had to overcome many hurdles, from states’ reluctance to participate, to critics’ predictions of unaffordable coverage, to unexpectedly tight money.

A quirk in the law gave generous funding for consumer outreach in states with their own marketplaces, but little for states with a federal exchange. That could be a problem since polls show that most Americans know little about how the law affects them.

There are also technical challenges: Obamacare supporters like to compare shopping on the exchanges to buying an airplane ticket on Travelocity or Expedia, but building the back-end system is far more complicated, requiring computers at state and federal agencies to be able to talk to one another in real time to verify an individual’s income and citizenship status, and determine eligibility for federal subsidies or Medicaid, the state-federal insurance program for the poor. That system also needs to connect with the computers run by insurance companies.

The biggest questions, though, revolve around who will show up and whether they will be able to afford coverage that takes effect Jan. 1 — especially the young and healthy, who will need to buy insurance in significant numbers to balance the costs of insuring the sick, who can no longer be turned away. The law requires most Americans to carry insurance in 2014, but some fear that the first-year penalties of $95, or 1 percent of income, won’t be a strong enough inducement.  If mostly older, sicker people show up, insurers will pass on their health care costs in higher premiums that will make coverage for all individuals less affordable over time.

Political Backdrop

All of these challenges are occurring in a politically charged environment in which both parties are already spinning developments to buttress their positions on the law. While the law’s effectiveness won’t truly be known for several years, underwhelming enrollment and high premiums could turn public opinion against Democrats before next year’s elections.

When government auditors released a report last week, for instance, saying the Obama administration faced challenges to open the federally run exchanges in time, Republicans pounced.

“The (Government Accountability Office) report underscores the sad reality that the administration is still woefully unprepared for implementation despite the law being signed over three years ago,” said Rep. Fred Upton, the Michigan Republican who chairs the House Energy and Commerce Committee. 

President Barack Obama insists the exchanges will open on time and coverage will be affordable, although he acknowledges there will be bumps along the way, as there would be for any new program. On Monday, the administration relaunched healthcare.gov, the web portal for the federally run exchanges, and opened a 24-hour-a-day call center to help consumers prepare for open enrollment by calling a toll-free number at
1-800-318-2596.

Short on money and worried about starting outreach during the summer vacation period, the administration won’t launch its major public campaign until at least mid-September. But supporters of the law, such as the nonprofit Enroll America, are planning to use the 100-day milestone to start their own efforts.

Several states running their own exchanges, including Connecticut, Colorado and Kentucky, have recently begun airing television commercials about the new options that will be available Oct. 1, for coverage that begins in January. Open enrollment runs through March.

“People need to know this is coming so they can start thinking about it,” said Carrie Banahan, executive director of the Kentucky exchange that recently rebranded itself as Kynect — Kentucky’s Healthcare Connection. “Insurance is complicated and we wanted to try to make it easily understandable as possible,” she said.

Kentucky’s exchange, which expects up to 200,000 people to enroll in the first year, has been testing whether its computer systems can connect with federal agencies, as well as its Medicaid program. “”We are meeting all our deadlines and are on track,”” Banahan said.

This summer, it plans to begin marketing at minor league baseball games and the state fair. In September, it plans to have a booth at one of the state’s biggest early fall events — the Bourbon Festival.

The state-run exchanges are at various levels of readiness. California’s, for example, has approved insurance plans it will offer and awarded money to groups that will train guides to assist consumers. Idaho, whose legislature did not approve the exchange until March, has not even selected a name or chosen a vendor to build its website, said Stephen Weeg, chairman of the exchange. “We are going to have to be like Star Wars and do everything at hyper-speed,” he said.  

Nevada’s To Do List

Nevada’s Hager said that state will not start its publicity push until Oct.  7 so the exchange has time to work out any problems before too many consumers rush in.

In the next three months, it must certify health plans, test computer systems and begin an outreach effort that will include television and radio ads and knocking on doors. The exchange, which will use Nevadahealthlink.com in its marketing, hopes to enroll 118,000 people in first year, Hager said. 

Though most of the focus is on states and the federal government, hundreds of private companies are doing much of the work, including information technology firms such as Xerox, and religious organizations and chambers of commerce,that will educate individuals and small employers about their new insurance options.

Insurers, who have the most to gain from robust enrollment, including Florida’s largest insurer, plan to launch education campaigns to counter widespread ignorance about the health law.

“This is a huge communication and education undertaking for us,” said Jon Urbanek, senior vice president of commercial markets for Florida Blue, the Blue Cross and Blue Shield in that state. Among people eligible for subsidized coverage, he added, “a lot of those don’t even know what health insurance is.””