WASHINGTON The Citizenship and Immigration Services unit of the U.S. Department of Homeland Security has revamped its Form I-9, which employers must complete for all newly hired employees.

The revised form, which was supposed to become effective in January, took effect last month. Previous versions of the form may no longer be used.

The new I-9 shows a revision date of "02/02/09" and an expiration date of "06/30/09." The revision date can be found in the lower right-hand corner of the form.

The expiration date does not necessarily mean it will be revised again before it expires. Certain forms must carry an expiration date to comply with requirements from the Office of Management and Budget, and the expiration date imposed by the OMB could be extended without further revision to the form.

The basic purpose of the I-9 is to determine the eligibility of individuals to work legally in the United States. All employers must complete and retain a Form I-9 for each individual they hire for employment in the U.S. This includes both citizens and noncitizens.

Using the form, the employer must examine the employment eligibility and identity document(s) an employee presents to determine whether the document(s) reasonably appear to be genuine and relate to the individual. Information from the documents is recorded on the form. A list of acceptable documents can be found on the last page of the form.

One of the most significant changes to the form is that expired documents are no longer acceptable. The previous I-9 allowed employers to accept expired U.S. passports, as well as expired identification documents from the list on the form.

Employers do not need to replace previously completed I-9s with the new version. Any completed I-9 which was valid at the time remains valid, and must be kept for the required retention period.

However, the older versions of the I-9 can no longer be used. For example, when an employee must be reverified because employment authorization has expired, employers must use the revised Form I-9 with its new list of acceptable documents.