Regulations have never been published by the INS or USCIS to fill in the gaps and ambiguities in AC21. Instead, the agency has issued several policy memos that explain who is eligible to "port". The discussion below is based in large part on those memos, which do not have the force law and which can be changed at any time by the USCIS, Congress or the courts.

"Portability" in the context of AC21 refers to the ability to change employers without invalidating: 1) H-1B status, 2) an approved labor certification, or 3) an approved I-140. A green card (i.e., I-140/I-485) applicant may have invested many years seeking the labor certification and waiting for the USCIS to process the green card applications. Portability can enable the move to another job without requiring the applicant to start all over again from the beginning.

Normally, the employee will lose all of the benefits of the labor certification if he or she loses the underlying job (i.e., quits or is fired) before 1) the labor certification is approved, or 2) within the first 180 days after filing the I-485.

On the other hand, the approved labor certification is almost always portable after the 180^th day after filing the I-485. In that case, the employee can continue to use the labor certification and/or the approved I-140 to become a permanent resident as long as the new job is in the "same or similar occupation." That is true even if:

In most cases an employee can change jobs 180 days after filing the I-485, without having to get a new labor certification or file a new I-140. However, before changing companies, employees should get the advice of an attorney who is familiar with the old job, new job, and current status of the I-140/I-485, and there should be a comprehensive analysis and strategy in place before leaving the initial job.

AC21 also provides for changing employers and retaining H-1B status as soon as the H-1B petition for the new company is received by the USCIS. This H-1B portability applies even after the initial H-1B status expires, if the new H-1B petition is filed before it expires.

For example, an employee who works for Company A, with H-1B status valid to June 1, 2009, may get a job offer from Company B in May 2009. If Company B files an H-1B petition by overnight courier on May 18, 2009, the employee can begin working on May 19, 2009. If the employee then decides to work for Company C on June 15, she can do so, even though it is past the June 1 expiration date and even though the Company B petition is not yet approved (as long as Company C submits an H-1B petition by June 15). This would be a good case for Premium Processing (i.e., paying the USCIS an additional $1000 for expedited processing), because if Company B withdraws its H-1B petition before the Company C petition is approved, the "bridge" would be broken, and the H-1B status would no longer be portable.

Premium Processing is also appropriate when changing employers if there is a question as to whether the H-1B petition with the new company will be approved. For example, there may be an issue as to whether the new job is a professional position that will support H-1B status. Portability applies only if the new H-1B petition is approved. If it is denied, the denial is retroactive to the date of filing. Although the portability laws provide that the employment with the new company is lawful until the date of denial, once it is denied the employment is no longer authorized and the employee is out of status. If there is a possibility of denial, it might therefore be advisable to wait until the new H-1B petition is approved, rather than rely on the portability provisions. In my experience though, most H-1B transfers are ultimately approved, and it is a rare case in which the H-1B portability provisions of AC21 should not be used.

There are two bases for extending H-1B status beyond the normal limit of 6 years. First, it can be extended if a labor certification or I-140 is filed by the end of the 5^th year in H-1B status. Second, it can be extended if the employee cannot file for or complete adjustment of status because the immigration quota is not yet current.

In order to extend H-1B status beyond six years, the H-1B petitioner does not have to be the employer that filed the labor certification. The employee is entitled to continue to extend the H-1B status until:

a) The labor certification is denied or withdrawn;

b) The I-140 is denied or withdrawn; or

d) The I-485 is denied or approved.

An H-1B employee who is working for Company A (which filed a labor certification before the end of the 5^th year), can transfer to Company B, and continue to extend H-1B status beyond the 6^th year, as long as the labor certification (filed by Company A) is still pending. Of course, that would require Company A’s cooperation not to withdraw the labor certification, and perhaps even to pursue the labor certification to completion.

An I-140 remains pending until the conclusion of an administrative appeal. By way of example, assume that the basis for extending the H-1B status is an Outstanding Researcher or National Interest Waiver petition (I-140) filed before the end of the 5^th year in H-1B status. If the I-140 is denied, the petitioner has 30 days to appeal the decision to the Administrative Appeals Office (AAO). The AAO often takes over a year to process such appeals. The employee could extend his or her H-1B status beyond six years at any time before a final decision is made on the appeal.

In some cases, an employee may be able to resume H-1B status beyond the six-year limit even though he or she is no longer in H-1B status or out of the country.

H-1B extensions based on the unavailability of the per-country quota would normally be requested for a period of three years. Although AC21 itself refers to "one-time protection," the USCIS will grant additional extensions if three years is not enough time for the quota to become current. In order to extend H-1B status based on the per-country quota, the I-140 (not just the labor certification) must be approved.