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.