When a former employee returns to your company, one of the first questions is whether you need to complete a brand new Form I-9 or use the existing one. The answer depends on how long ago the original Form I-9 was completed — and whether it's still on file.
USCIS gives employers two options when rehiring someone, but only if you're within the right timeframe. Get it wrong and you could face fines during an I-9 audit, even if the employee is fully authorized to work. Here's exactly how to handle it.
If you rehire an employee within 3 years of the date their previous Form I-9 was completed, you have two options:
If the rehire happens more than 3 years after the original Form I-9 was completed, you must complete a new Form I-9. There is no option to use Supplement B in this case.
This is often called the "3-year rule" — and it's measured from the date the original I-9 was completed, not the employee's last day of work.
If you're within the 3-year window and choose to use the existing Form I-9, follow these steps:
Confirm the original I-9 is still on file and relates to the employee being rehired. If you cannot find the original, or if it's illegible or incomplete, you must complete a new Form I-9 instead.
Review the original Section 2 (or a previous Supplement B entry) to determine whether the employee's documentation has expired or their work authorization has ended.
Note: Never reverify List B (identity-only) documents. You also never need to reverify U.S. passports, U.S. passport cards, or Permanent Resident Cards (Form I-551) — even if they have expired. These documents do not require reverification.
If the version of the previously completed Form I-9 has expired, you must complete Supplement B on the current version of the form and attach it to the original.
The employer (or authorized representative) signs and dates Supplement B. The employee does not need to complete a new Section 1.
A new Form I-9 is required in any of these situations:
If you complete a new I-9, follow the standard process: Section 1 on or before the employee's first day of work (in this case, their rehire date), and Section 2 within 3 business days.
Our compliance team has helped hundreds of companies navigate rehire scenarios — from seasonal workers to post-merger onboarding. Schedule a free compliance call to talk through your specific situation, or try our I-9 Risk Calculator to assess your overall compliance risk.
Not every return to work counts as a rehire. USCIS distinguishes between employees who are rehired (left and came back) and employees in continuing employment (never truly left). This distinction matters because continuing employees do not need any updates to their I-9.
The following situations are generally considered continuing employment — no new I-9 or Supplement B is needed:
The key question is whether the employee had a reasonable expectation of employment at all times. If they did, they're a continuing employee — not a rehire.
Factors USCIS considers when evaluating reasonable expectation include:
If your company participates in E-Verify, the answer depends on which I-9 option you choose:
However, if the original E-Verify case was never created, was closed before receiving a final result, or resulted in anything other than "Employment Authorized," you should complete a new Form I-9 and create a new E-Verify case.
This is one of the most common rehire situations, especially in agriculture, hospitality, and construction. If the employee returns annually and you maintain their I-9 on file, you can use Supplement B each time they return — as long as the original I-9 is less than 3 years old and their work authorization hasn't expired. Many employers in seasonal industries choose to treat these workers as continuing employees with a reasonable expectation of returning, which avoids the Supplement B process altogether.
Within the 3-year window, so you have the choice: new I-9 or Supplement B. If their original documents are still valid, Supplement B is the simpler path — just record the rehire date and sign.
Beyond the 3-year window. You must complete a brand new Form I-9 with full Section 1 and Section 2. You may have already disposed of the original I-9 per retention rules.
USCIS does not require an updated I-9 for name changes, but it is recommended. If you're completing Supplement B for a rehire and the employee's legal name has changed, you can note the name change in Supplement B. If you prefer a clean record, complete a new Form I-9 instead.
When one company acquires another, the new employer has two options for acquired employees:
If an acquired employee later leaves and is rehired by the new company, the standard 3-year rehire rules apply — measured from whenever that employee's most recent I-9 was completed.
If a temporary staffing agency employee transitions to a permanent role at the client company, this is typically a new hire for the client — even if the person has been working at the client's site for months. The client company must complete its own Form I-9 for the employee. The staffing agency's I-9 does not transfer.
If you rehire someone within 3 years of when their original Form I-9 was completed, you can either complete Supplement B on the existing I-9 or start a new one. After 3 years, a new Form I-9 is required. The clock starts from the I-9 completion date, not the employee's last day of work.
Yes. A name change does not prevent you from using Supplement B. You can note the new legal name in Supplement B. Alternatively, if you want a cleaner record, you can complete a new Form I-9 with the current name.
Not necessarily. Seasonal employees who return on a regular basis with a reasonable expectation of employment may qualify as continuing employees, in which case no I-9 updates are needed. If they are treated as rehires, you can use Supplement B as long as the original I-9 is within the 3-year window.
If the original Form I-9 is lost, destroyed, or was never properly completed, you must complete a brand new Form I-9 — even if the rehire is within the 3-year window. Supplement B requires the original I-9 to exist and be legible.
It depends on how the acquiring company handled the transition. If they chose to treat acquired employees as continuing employees and retained the original I-9s, then the standard 3-year rehire rules apply if the employee later leaves and returns.
Rehire compliance is only as good as your I-9 recordkeeping. If you can't quickly locate an employee's original I-9 and determine whether it's still within the 3-year window, you're already at risk. i9 Intelligence helps companies manage I-9 compliance electronically — including automated Supplement B tracking, remote Section 2 verification for rehires in any state, and full I-9 audits to catch problems before ICE does.
