Conditional certification in FLSA collective actions is the court order that lets a single worker’s wage lawsuit expand into a group case by authorizing notice to other employees who may have suffered the same pay violations and inviting them to opt in. It is not a ruling on the merits and it is not permanent. It is a gatekeeping decision about whether other workers should hear about the case, and the evidence you need to obtain it now depends heavily on which federal circuit you are in.
Why Conditional Certification Matters
The right to sue as a group for unpaid minimum wages, unpaid overtime, or tip violations comes from 29 U.S.C. § 216(b), which lets employees sue on behalf of themselves and “other employees similarly situated.”1Office of the Law Revision Counsel. 29 USC 216 – Penalties Unlike a Rule 23 class action, where everyone who fits the definition is included unless they opt out, a § 216(b) collective works the opposite way.2Legal Information Institute. Federal Rules of Civil Procedure Rule 23 – Class Actions No one becomes a plaintiff unless they file a written consent form with the court.
That opt-in rule is why conditional certification exists. Without a court-authorized notice reaching potential members, most workers never learn about the lawsuit at all. The Supreme Court confirmed in Hoffmann-La Roche Inc. v. Sperling that district courts have discretion to facilitate that notice and manage the joinder of additional plaintiffs.3Legal Information Institute. Hoffmann-La Roche Inc. v. Sperling, 493 US 165 What the Court never spelled out was the standard employees must meet before that notice can go out. Lower courts filled the gap themselves, and they have not filled it the same way.
The Traditional Two-Step Approach
For decades the dominant framework has been the two-step process from Lusardi v. Xerox Corp., a 1987 district court decision that became the template across most federal courts.4United States Court of Appeals for the Fifth Circuit. Swales v. KLLM Transport Services, LLC It works like this:
- Step one, conditional certification. Early in the case, usually before significant discovery, the plaintiffs ask the court to authorize notice to potential opt-in members. The standard is lenient. Plaintiffs need only make a “modest factual showing” that other similarly situated employees exist.
- Step two, decertification review. After discovery, the defendant can move to decertify. The court applies a much stricter standard, examining whether the plaintiffs are truly similar enough for a single trial.
The low bar at step one has historically given plaintiffs a significant early advantage. In most cases, a handful of employee declarations describing a common pay practice were enough. Defendants had to wait until after discovery to mount a real challenge.
What Plaintiffs Show at Step One
Under the traditional framework, the evidence at conditional certification is deliberately minimal. Plaintiffs typically submit sworn declarations from the named plaintiffs and sometimes a few other workers describing shared job duties, a common pay policy, and the alleged violation.
The strongest motions tie the claims to a specific company-wide practice. If a group of technicians all followed the same handbook requiring setup tasks before clocking in, that handbook becomes the centerpiece. Pay stubs and time records showing consistent patterns of shorted hours across multiple employees reinforce the picture. Job descriptions help establish that workers with different titles were performing the same role under the same compensation rules.
What courts do not require at this stage is proof that the employer actually violated the law. Plaintiffs need only show enough to suggest a group of aggrieved workers probably exists. Vague allegations of unfair treatment fall short. Specific facts connecting a handful of employees to a common policy usually clear the bar.
Where the Standard Is Now Tougher
Beginning in 2021, three federal appeals courts concluded the Lusardi standard was too easy on plaintiffs and had no anchor in the statute. Where a case is filed now matters enormously.
Fifth Circuit: Swales v. KLLM Transport Services
In 2021 the Fifth Circuit rejected the Lusardi two-step outright, calling it a framework with “no anchor in the FLSA’s text or in Supreme Court precedent.” Under Swales, district courts must rigorously examine whether workers are similarly situated from the start, rather than deferring that analysis until after notice goes out.4United States Court of Appeals for the Fifth Circuit. Swales v. KLLM Transport Services, LLC The court told district judges to identify the material facts and legal questions at the outset, authorize whatever preliminary discovery is needed, and not ignore evidence just because it touches on the merits.
Sixth Circuit: Clark v. A&L Homecare
In 2023 the Sixth Circuit rejected the “fairly lenient” standard and adopted a new test. Plaintiffs must show a “strong likelihood” that the employees they want to notify are similarly situated. The court defined that threshold as greater than what is needed to create a genuine factual dispute but less than a preponderance of the evidence, drawing an analogy to the standard for preliminary injunctions.5Justia Law. Clark v. A&L Homecare and Training Center, LLC That is a meaningfully harder test than Lusardi’s modest factual showing.
Seventh Circuit: Richards v. Eli Lilly
The Seventh Circuit joined the trend in 2025, rejecting the modest factual showing standard and adopting a framework that asks whether, after considering evidence from both sides, a material dispute about similarity exists. Even when a dispute is present, the court told judges to exercise restraint before authorizing notice.
Three circuits rejecting Lusardi within four years is a real shift, though many district courts outside those circuits continue to apply the traditional approach.
What Happens After the Court Grants It
Once a court authorizes notice, the process looks similar under either framework. The court approves the specific language of a notice sent to employees who may qualify. The notice explains the lawsuit, describes the alleged violations, and tells recipients how to join by filing a written consent form.
The window for opting in is typically 60 to 90 days from the date the notice is sent. Employees can usually return consent forms by mail, email, or through an online portal managed by a third-party administrator. After the deadline, the legal teams compile the final roster. Anyone who did not opt in by the cutoff is not part of the case and is not bound by its outcome.
Why Timing Matters
FLSA claims carry a two-year statute of limitations for standard violations, extended to three years if the employer’s violation was willful.6Office of the Law Revision Counsel. 29 USC 255 – Statute of Limitations A willful violation generally means the employer either knew its conduct violated the FLSA or showed reckless disregard for whether it did.
The clock treats each plaintiff differently. For a named plaintiff, the limitations period stops running on the date the complaint is filed. For each opt-in plaintiff, it stops running only on the date their individual consent form is filed with the court.7GovInfo. Memorandum Opinion and Order – Cervenka v. Jumpp Logistics, LLC Every day a potential plaintiff waits to opt in is a day of back pay that may fall outside the recovery window. If a court takes eight months to rule on a conditional certification motion, workers who eventually opt in may have already lost months of potential damages.
Decertification at Stage Two
Under Lusardi, stage two arrives after discovery. The defendant moves to decertify, arguing that the full record shows the plaintiffs are not similarly situated. The standard is genuinely rigorous, and courts weigh several factors:
- Factual and employment settings. Did the plaintiffs work in the same locations, departments, and roles, or were their circumstances substantially different?
- Individualized defenses. Can the employer raise defenses that apply to some plaintiffs but not others, such as different supervisors applying policies differently?
- Claims and relief. Are the plaintiffs advancing the same legal theory and seeking the same type of compensation?
- Fairness and manageability. Can a single trial address the group’s claims without unfairly prejudicing the employer?
If the differences outweigh the similarities, the court decertifies. The opt-in plaintiffs’ claims are typically dismissed without prejudice, meaning they can file individual lawsuits, though most never do. Only the original named plaintiffs remain. In circuits that have abandoned Lusardi, the two-stage structure largely collapses, because the rigorous similarity analysis happens before notice goes out rather than after.
Arbitration Waivers Can Stop You Before You Start
Mandatory arbitration clauses with collective action waivers are the biggest obstacle many workers face before certification even becomes relevant. In Epic Systems Corp. v. Lewis (2018), the Supreme Court held that arbitration agreements requiring individualized proceedings must be enforced as written, even for FLSA claims.8Supreme Court of the United States. Epic Systems Corp. v. Lewis, 584 US 497 If you signed an arbitration agreement with a collective action waiver, you almost certainly cannot join a § 216(b) collective.
Drafting details matter. A class action waiver alone may not prevent collective action certification, because courts distinguish between Rule 23 class actions and § 216(b) collectives. Employers who want to block both typically need language that explicitly covers collective actions. If the waiver appears only inside an arbitration clause and the employer later waives its right to arbitrate, some courts have found the collective action waiver unenforceable as well.
Retaliation Protection for Participating
Federal law protects you from retaliation for participating in an FLSA collective, whether you file the original complaint, opt in, or testify. Under 29 U.S.C. § 215(a)(3), it is illegal for an employer to fire you or discriminate against you for exercising these rights.9Office of the Law Revision Counsel. 29 US Code 215 – Prohibited Acts If your employer retaliates, remedies include reinstatement, back pay, and liquidated damages equal to the back pay amount.1Office of the Law Revision Counsel. 29 USC 216 – Penalties The protection also extends to employees who are “about to testify,” so an employer cannot preemptively retaliate against someone it suspects will participate. That coverage matters most to current employees who opt in while still working for the defendant, a situation that understandably makes many workers nervous.