WASHINGTON – The Obama administration expects fewer than 10 million people to enroll in marketplace health coverage next year, far below the 13 million people that the Congressional Budget Office has projected.

The 2015 enrollment season for marketplace health insurance begins Saturday, and consumers can expect more coverage choices, a better functioning network and an easier enrollment process for most new first-time users, according to the Obama administration.

After last year's disastrous rollout of the HealthCare.gov website, the U.S. Department of Health and Human Services spent the past year upgrading, simplifying and fully testing the glitch-prone process that serves 36 states. Officials expect the redesigned and more muscular system to handle more than 125,000 concurrent users.

The CBO projected marketplace enrollment to reach 13 million in 2015, 24 million in 2016 and 25 million in 2017 as the program is fully implemented. That aggressive growth assumed a significant decline over the next two years in both employer-based insurance and non-marketplace individual coverage. But a new HHS analysis suggests the CBO projections may be unrealistic.

Senior administration officials say there's "mixed evidence" and "considerable uncertainty" about the CBO's expectation of a large two-year movement away from job-based coverage and individual coverage purchased outside the marketplace.

Those uncertainties and the history of slower enrollment growth in programs like Medicaid and the Children's Health Insurance Program suggest it could take four to five years — until 2019 — for the state and federal marketplaces "ramp-up" to 25 million enrollees.

As a result, the Obama administration expects only 9 million to 9.9 million people to enroll in marketplace coverage by the end of 2015. This year's enrollment period will run for just three months, Saturday through Feb. 15, instead of six months like last year.

Officials are promising a streamlined application process that will allow 70 percent of first-time HealthCare.gov enrollees to complete their coverage applications by navigating through just 16 computer screens, instead of 76. The remaining 30 percent whose household characteristics are more complex will use the traditional process.

Returning consumers already have received notices in the mail and in their HealthCare.gov accounts explaining the re-enrollment process. When they begin, 90 percent of their online application already will be filled out.

To ensure new coverage is effective on Jan. 1, 2015, applicants must complete the enrollment process no later than Dec. 15. People who don't re-enroll for 2015 will be auto-enrolled in the same plan.