When the crew comes back, you are standing at a fork — and both branches are fineable

Branch A

The prior Form I-9 is still within the retention period and you still have it

This is the branch where Supplement B (the block formerly known as Section 3) exists. Where an employee is rehired within three years of the date the original Form I-9 was completed, an employer may generally choose to update the existing form rather than start over — recording the rehire date in Supplement B and reverifying work authorisation at that point if it has expired. The word doing the work is may: it is ordinarily an option, not an obligation. What makes it attractive is that it keeps one continuous record for one person instead of two competing ones.

Branch B

More than three years have passed, or the prior form is gone

Outside the three-year window the option closes and a new Form I-9 is ordinarily required. The same is true in practice when the earlier form cannot be produced, was never completed, or was completed so defectively that updating it would simply extend a bad record. A new form is not a failure state — for many seasonal employers it is the cleaner default. The failure state is not knowing which branch you are on.

The one people get wrong

The employee never actually terminated

A worker who stays on the books through a slow season, is furloughed, or goes on approved leave and returns has generally not been rehired at all. No rehire means no Supplement B rehire entry and no new form. Employers with seasonal rhythms routinely paper a return that was never a separation, which creates an event in the file that did not happen in life — and a date an inspector will ask about.

The separate question

Their work authorisation expired while they were gone

Reverification and rehire ride in the same block and are two different triggers. A returning worker whose employment-authorisation document has lapsed generally needs reverification regardless of which branch of the fork you took, and lawful permanent residents' green cards are ordinarily not reverified at all. Treating every returning seasonal worker as a reverification event is over-documentation; treating none of them as one is a missed reverification. Both are findings.

The trap in the middle

You rehired them, and nobody looked for the old form

This is the common case and it does not feel like a decision at all. The returning worker is onboarded as a new hire because that is what the system does, and the fork is resolved by default rather than by choice. It produces a perfectly clean-looking new I-9, which is exactly why it survives most self-audits.

The compounding one

Several returns over several seasons

Three seasons of the same crew can leave one worker with three forms in three different places, each internally consistent, none referencing the others. Nobody set out to build that. It is the arithmetic of an annual intake with no rule about which branch to take, and it is what an employee-history reconciliation surfaces in about a minute.

A brand-new I-9 for someone who should have been updated on the old one

This is the error that hides best, because the artifact it produces is a clean form. Reviewed on its own, a new I-9 for a returning worker passes every checklist — signed, dated, complete. It only becomes visible next to the prior form for the same person, which is in the terminated-employee archive nobody pulled. Whether a duplicate is treated as a defect or merely as untidy depends on the facts, but the practice has a second cost that is not ambiguous: two forms for one person means two hire dates in the record, and you now have to explain which one is true.

Supplement B used well outside the window

The mirror error. An employer who prefers updating the existing form keeps doing it at season four and season five, past the point where the option was available, and ends up with a single form carrying a stack of rehire entries stretching years beyond the original completion date. The form looks diligent. The dates on its face show the three-year rule was not applied.

The retention clock gets recalculated wrong — or not at all

Retention for a Form I-9 is generally measured as three years after the date of hire or one year after employment ends, whichever is later. A rehire moves the employment-end date, which moves the disposal date with it. Employers who purge on a fixed annual schedule destroy forms for returning seasonal workers while those forms are still required, and an I-9 that cannot be produced is not a technical problem — a form that does not exist cannot be corrected. Employers who never recalculate go the other way and keep everything forever, which is merely wasteful.

The rehire date entered is the date the paperwork got done

Seasonal intake happens in a rush and the file work often catches up a week later. The rehire date belongs to the day the employee actually resumed work for pay, not the day somebody reached the filing cabinet. Backfilling a block with the convenient date rather than the true one is a different and much more serious category of problem than being late, and lateness is the thing it is usually meant to hide.

Nobody owns the decision, so the crew leader makes it

In snow, irrigation, harvest, packing, production and holiday-peak work, returning workers are onboarded by whoever is running the intake that week. Without a written rule they will each resolve the fork differently, and the variation itself becomes a finding — the same employer treating identical situations three different ways across three sites. This is the returning-worker version of the delegation problem covered in the Section 2 authorized-representative guide.

Step 1

Before the season, list who is coming back

Every returning-worker error begins with the return being a surprise to the file room. A roster of expected returns, built before the intake starts, converts a scramble into a lookup. It is also the single cheapest step on this page.

Step 2

Pull the prior Form I-9 first — then decide the branch

Retrieve the earlier form before onboarding, not after. With it in hand the fork answers itself: check the date the original was completed, and whether three years have passed. Without it, the default takes over and a duplicate gets created. The decision costs a minute when the form is in front of you and cannot be made at all when it is not.

Step 3

Write down one rule and apply it everywhere

Pick the employer's standard approach for returns inside the window, name who may execute it, and require the prior-form lookup in both cases. Consistency is worth more here than which branch you prefer, because an inspector comparing sites is looking for the pattern rather than the preference.

Step 4

Separate the rehire question from the reverification question

Handle them as two checks in sequence. First: is this a rehire at all, and which branch. Second, and independently: has this person's work authorisation lapsed, and is it a category that is reverified. Collapsing the two is how employers end up reverifying permanent residents they should not have touched and missing expirations they should have caught.

Step 5

Recalculate the disposal date after every return

Each rehire resets the later-of calculation. Update the retention date at the same moment the rehire is recorded, while the dates are in front of you. Purging on a calendar rather than on the arithmetic is how required forms get destroyed by a process that believed it was being tidy.

Step 6

Audit by employee, not by form

This is the change that finds the problem. Sort the whole file set by person rather than by form and look for anyone holding more than one. Every duplicate is a fork that was resolved by accident, and no form-by-form review will ever show you one — each of those forms looks fine by itself.