Washington- The Obama administration acknowledged on Friday that about 800,000 Healthcare.gov customers received incorrect tax information from the federal government. Officials have advised that people who have received the wrong information should postpone filing their 2014 returns.

The errors were discovered on 1095-A forms sent to Healthcare.gov customers who had signed up in 2014 and received tax credits to compensate for the premium costs. Those statements are used to determine if people received an appropriate tax credit. Forbes reported that the incorrect 1095-A forms “included the monthly premium amount of the second lowest cost Silver plan for 2015 instead of 2014.”

According to Andy Slavitt, the administrator at the Centers for Medicare and Medicaid Services, as many as 20% of statements sent out contained the wrong local premium.

Officials estimate that about 50,000 people who received incorrect information have already filed their returns. The remainder of the recipients will be asked to wait until corrected statements are issued before filing their taxes.

California’s health exchange, Covered California, issued a statement on Thursday revealing a similar mistake in sending about 100,000 incorrect forms to people in the state. California appeared to know of the inaccuracies before issuing the forms to meet the February 2nd deadline; Covered California spokesman Dana Howard told news station KPIX 5 that “We did not want to hold up sending out the 1095s to everybody, so that we can correct those that we did have.”

The Health and Human Services Department also announced on Friday an extended health insurance enrollment period, stating that “This special enrollment period will allow those individuals and families who were unaware or didn’t understand the implications of this new requirement to enroll in 2015 health insurance coverage through the federally facilitated marketplace.” Between March 15th and April 30th, people previously uninsured will be able to sign up for insurance, but will be expected to affirm that they were unaware of the healthcare law’s requirement to have insurance or pay a fine when they filed their taxes.