Due to a change in U.S. government procedures involving the Obamacare health care law, over 400,000 immigrants have had their insurance coverage canceled this year, reported the Associated Press.

The procedural change has resulted in a shorter timeframe for immigrants to resolve citizenship and eligibility issues, causing 423,000 of them to lose their taxpayer-subsidized benefits, almost four times more than the 109,000 people who lost coverage for similar reasons in all of 2014.

The health care law stipulates that only U.S. citizens and legal residents are eligible for coverage, and this year, the law only provides a 95-day window for resolving documentation issues. That time frame was not in place in 2014 since it was the first year HealthCare.gov offered expanded coverage, according to AP.

The National Immigration Law Center said that it believes most of the people who lost coverage were legal residents and citizens, but were mistakenly targeted by the inefficient and complicated document-checking system.

The center's health policy analyst, Angel Padilla, said that undocumented immigrants would be foolish to apply for subsidized benefits they are not eligible for because they would risk alerting a federal agency to their illegal status.

"Somebody who is trying to submit documents over and over ... is someone who believes they have an eligible immigration status," Padilla told AP.

He said that the 95-day window isn't necessarily the problem, but rather, people are confused as to which documents they need to fill out. "If it was clearer what the consumer needed to do, we wouldn't have the numbers that we have," Padilla explained.

AP noted that the number of people who had coverage terminated might be higher than reported, as the 423,000 figure does not include two states with some of the largest immigrant populations, California and New York, who operate their own exchanges.

Many Republicans lawmakers have criticized the health care system for doling out benefits to people not legally entitled to them. In 2014, investigators for the congressional Government Accountability Office demonstrated how easy it was to game the system by successfully enrolling fictitious people through HealthCare.gov, and then renewing their coverage for 2015. The probe also found issues with how the website's communication department informs people of issues with their applications.