CHICAGO — A poorly designed federal system prevented perhaps thousands of immigrants from enrolling in coverage under President Barack Obama's health care overhaul, according to a preliminary report from an Illinois advocacy group.

The Associated Press was given the report by the Illinois Coalition for Immigrant and Refugee Rights on Wednesday, a day before its planned release was abruptly postponed. The report says federal phone operators were misinformed about immigrant eligibility, a credit agency verifying identities couldn't handle languages other than English and Spanish and some immigrants were incorrectly referred to Medicaid, causing their applications to be frozen.

"These issues were the result of a poorly designed system that was not planned and implemented with immigrants and refugees in mind," the report states. The 14-page report provides a new level of detail about previously known roadblocks for eligible immigrants.

Immigrants who remain uninsured could face fines under the health law, as well as high medical bills from accidents or unforeseen illness. People in the United States illegally aren't eligible for coverage under the law.

The group behind the report had a $1.25 million grant to help enroll Illinois immigrants eligible for the law's new coverage options and was able to enroll 10,000 immigrants by the March 31 deadline through 29 community organizations. The group estimates that nearly 260,000 uninsured Illinois immigrants were eligible for coverage under the law. It's unclear how many are still uninsured because other groups may have signed up immigrants.

The Illinois group had planned to release its report Thursday, but canceled two hours before a planned media briefing "to make some final revisions to the report and have discussions with our Congressional delegation," according to an email sent to the AP Thursday from the group's communications director, Monica Trevino. She said the revised report would come out officially in a few weeks.

Luvia Quinones, one of the report's authors, said Thursday the revised report won't be toned down, but will include "a few other stories to reflect the rest of the immigrant and refugee community."

The preliminary report says:

— Electronic identity verification systems generally didn't work, requiring immigrants to upload documents such as visas, passports and green cards. Uploading also often failed, requiring immigrants to mail their paperwork to a Kentucky processing center.

— Legal permanent residents, or green card holders, aren't eligible for Medicaid until they've been in the country for five years, but they were eligible to buy subsidized coverage on the marketplace. But the federal online system incorrectly referred many of them to Medicaid, which then would effectively freeze their applications. Federal phone operators also were misinformed or poorly trained about the five-year rule.

— Immigrants and refugees faced additional enrollment steps and procedures that caused discouraging delays and some gave up on the process. Enrollment counselors often made two to three appointments with clients spending up to four hours at each meeting, trying to upload documents and helping them talk to federal phone operators.

— The intensive time required of counselors caused them to work nights and weekends and "took away time they could devote to outreach and assisting more uninsured families."

— In Illinois, official educational material "was written in a complex language and was not translated correctly" and was available only in English and Spanish.

— A credit agency that played a key role in the federal system's verification of applicant's identification lacked operators who understood languages other than English and Spanish.

Associated Press medical writer Carla K. Johnson can be reached at