For most H-1B workers, six years is the general maximum period they may remain in the United States in H-1B status. But reaching the six-year limit does not always mean the employee must stop working or leave the United States.

For employees who have started the employment-based green card process, the American Competitiveness in the Twenty-First Century Act, commonly known as AC21, provides important exceptions that can allow H-1B status to continue beyond six years.

There are two primary paths employers and employees should understand. One can provide H-1B extensions in one-year increments based on the timing of the PERM labor certification or immigrant petition process. The other can provide extensions of up to three years at a time when the employee has an approved I-140 but cannot complete the green card process because an immigrant visa is unavailable.

Although these provisions are often discussed together, they have different requirements. Understanding those differences becomes particularly important when an employee changes employers, receives an I-140 approval from a prior employer, or sees a priority date become current.

The General Six-Year H-1B Limit

H-1B workers are generally limited to six years in H-1B status. Employers should therefore determine an employee’s expected H-1B maximum stay date well before the employee approaches the end of that period.

For employees pursuing permanent residence through employment, however, Congress created exceptions recognizing that the green card process can take years to complete. Delays may arise during the PERM and I-140 process, while other employees may have an approved immigrant petition but remain unable to obtain permanent residence because of immigrant visa backlogs.

AC21 addresses both situations.

Path One: One-Year H-1B Extensions Based on the 365-Day Rule

Sections 106(a) and (b) of AC21 allow certain H-1B workers to receive extensions beyond the normal six-year limitation in one-year increments.

A worker may qualify when at least 365 days have elapsed since the filing of:

• a qualifying PERM labor certification application; or
• a qualifying employment-based immigrant petition, such as Form I-140, where no labor certification was required.

This rule is frequently described as requiring the PERM to have been “pending for 365 days.” That description can be misleading.

The important issue is generally whether 365 days have elapsed since the qualifying filing, not whether the PERM itself remained pending for the entire 365-day period. For example, a PERM could be filed, approved several months later, and followed by a timely filed I-140. The original PERM filing date may still establish the relevant 365-day milestone.

Consider an employee whose PERM was filed on January 15, 2026, and whose six-year H-1B limit will be reached on March 1, 2027. By the time the employee reaches the six-year limit, more than 365 days will have elapsed since the PERM filing. Assuming the other requirements are satisfied and the permanent residence process remains viable, the employer may be able to request additional H-1B time in one-year increments.

USCIS regulations also permit an employer to file the H-1B petition before the 365th day, provided the qualifying filing will have reached the 365-day mark before the requested period of H-1B admission under the exemption begins.

This makes early green card planning critical. If an employer waits too long to begin PERM, the employee may reach the six-year H-1B limit before satisfying the 365-day requirement.

What Happens After the PERM Is Approved?

PERM approval does not necessarily eliminate eligibility for a one-year AC21 extension.

If the PERM is approved, the employer generally moves to the next stage by filing Form I-140. The regulations allow one-year extensions to continue while the qualifying permanent residence process remains unresolved, subject to applicable limitations.

Employers should nevertheless be careful about delays after PERM approval. A certified PERM generally has a limited validity period for filing the I-140. Allowing the permanent residence case to lapse can jeopardize the basis for future H-1B extensions.

The one-year extension mechanism therefore should not be viewed as an indefinite H-1B benefit independent of the green card process. Its continued availability depends on the underlying permanent residence case and the circumstances of that case.

Path Two: Approved I-140 and Three-Year H-1B Extensions

A separate provision, Section 104(c) of AC21, can provide a significantly longer extension.

An H-1B worker who is the beneficiary of an approved employment-based immigrant petition in the EB-1, EB-2, or EB-3 categories may qualify for H-1B extensions in increments of up to three years when the worker is eligible for permanent residence except that an immigrant visa is unavailable because of applicable immigrant visa limitations.

In practical terms, this provision is particularly important for workers born in countries with substantial employment-based immigrant visa backlogs.

For example, suppose an Indian-born H-1B employee has an approved EB-2 I-140 with a priority date that is not current under the applicable Visa Bulletin. The employee may be unable to file for or complete permanent residence for years despite having an approved I-140. If the requirements are satisfied, the employer may request an H-1B extension of up to three years under AC21 Section 104(c).

Unlike the one-year extension provision, there is no requirement that the PERM or I-140 have been filed at least 365 days earlier. The key considerations include the approved I-140 and the unavailability of an immigrant visa.

Importantly, USCIS regulations require the employer to establish visa unavailability as of the date the H-1B petition is filed.

Can a New Employer Use an I-140 Approved for a Previous Employer?

This is one of the most important practical questions when hiring experienced H-1B workers.

Suppose Company A sponsored an employee for permanent residence and obtained an approved I-140. The employee later accepts an H-1B position with Company B. The employee is approaching the six-year H-1B limit, and the priority date associated with the approved I-140 remains backlogged.

Can Company B rely on the I-140 filed by Company A when requesting additional H-1B time?

Potentially, yes.

The H-1B employer requesting the extension does not necessarily have to be the employer that obtained the I-140 approval. If the employee remains the beneficiary of a qualifying approved I-140 and otherwise meets the requirements for the AC21 exemption, a different employer may be able to rely on that approval when requesting additional H-1B time.

This does not, however, mean that Company B automatically inherits Company A’s green card case.

The ability to rely on an approved I-140 for an H-1B extension is distinct from whether that petition can ultimately support the employee’s permanent residence with the new employer. Depending on the circumstances, Company B may still need to begin its own PERM and I-140 process for the employee to obtain permanent residence through Company B.

Employers should also determine whether the prior I-140 remains valid for the benefit being requested. Withdrawal or revocation of an I-140 can affect the analysis, and the timing and reason for the withdrawal or revocation can matter.

What If the Employee’s Priority Date Becomes Current?

This is where the distinction between the one-year and three-year AC21 provisions becomes especially important.

The three-year extension under Section 104(c) is based on the employee’s inability to obtain permanent residence because an immigrant visa is unavailable. USCIS regulations require the petitioner to demonstrate that visa unavailability exists when the H-1B petition is filed.

If the employee’s priority date becomes current and an immigrant visa is available, the employee may no longer qualify for a three-year extension on that basis.

That does not necessarily mean the employee has no way to extend H-1B status.

Depending on the history of the PERM, I-140, and permanent residence case, the employee may separately qualify for one-year extensions under the lengthy-adjudication provisions of AC21.

There is another important limitation. USCIS regulations generally restrict future one-year AC21 extensions when the foreign national fails to apply for adjustment of status or an immigrant visa within one year after an immigrant visa has remained continuously available, subject to regulatory exceptions.

For that reason, an employee whose priority date becomes current should not simply assume that an existing AC21 strategy can continue indefinitely. Visa Bulletin movement can change which H-1B extension provision is available and may trigger the need to take action on the permanent residence case.

One Employee May Use Different AC21 Provisions Over Time

The two AC21 extension mechanisms are not mutually exclusive. An employee’s eligibility can change as the green card case progresses.

Consider this timeline:

An employer files PERM while the employee is in the fifth year of H-1B status. By the employee’s six-year maximum stay date, more than 365 days have elapsed since the PERM filing. The employer obtains a one-year H-1B extension under AC21.

The PERM is later approved, and the employer files an I-140. Once the I-140 is approved, the employee’s priority date remains significantly backlogged. On a later H-1B filing, the employee may qualify for an extension of up to three years based on the approved I-140 and visa unavailability.

Years later, the employee’s priority date becomes current. At that point, the employer and employee must reevaluate the basis for any future H-1B extension and determine what steps should be taken toward permanent residence.

The correct AC21 strategy therefore depends not only on whether an employee has a PERM or approved I-140, but also on when each filing occurred, the current status of the green card case, and immigrant visa availability at the relevant time.

Employers Should Track Green Card and H-1B Timelines Together

Employers sponsoring H-1B workers for permanent residence should not treat the H-1B and green card processes as completely separate matters.

At a minimum, employers should monitor the employee’s H-1B maximum stay date, any available recapture time, the PERM filing date, I-140 filing and approval dates, the employee’s priority date, and movement in the Visa Bulletin.

This is particularly important when hiring an H-1B employee who already has an approved I-140 from another company. Understanding the employee’s immigration history before filing the H-1B petition can determine whether the employer can request one year, three years, or another period of H-1B validity.

The six-year H-1B limit is therefore not always the end of H-1B eligibility. For employees with employment-based green card cases underway, AC21 can provide valuable additional time. But the one-year and three-year extension provisions operate differently, and changes in the PERM, I-140, employer, or priority date can significantly affect the analysis.

Employers approaching these deadlines should review the employee’s complete H-1B and permanent residence history early enough to identify the appropriate extension strategy before the six-year clock runs out.

By: Felipe Jimenez

Felipe Jimenez is an Associate Attorney at Reddy Neumann Brown PC. He works in the Non-Immigrant Visa (NIV) Department where he assists clients through all phases of the non-immigrant visa process.

Reddy Neumann Brown PC has been serving the business community for over 20 years and is Houston’s largest immigration law firm focused solely on US. Employment-based immigration. We work with both employers and their employees, helping them navigate the immigration process quickly and cost-effectively.