29 U.S.C. § 185
LMRA § 301: suing over a union contract, and the six-month clock that only sometimes applies
A federal claim in United States district courts · Last verified August 26, 2026
Section 301 covers two different lawsuits that share a statute and almost nothing else.
A straight § 301 suit is institutional — a union and an employer litigating a collective bargaining agreement.
A hybrid suit is an individual employee suing both the employer and their own union. It carries a six-month deadline, and the employee must prove both defendants breached their obligations to recover from either.
The six months applies only to the hybrid claim. Sources routinely state it as the § 301 period generally. That is wrong, and it is the error most worth guarding against here.
What the claim is
Straight § 301: a union sues an employer for violating the collective bargaining agreement, or to compel arbitration or enforce an award. Employers sue unions too.
Hybrid § 301 / duty of fair representation: you were fired, your union took your grievance and then dropped it, settled it, or handled it so badly that arbitration never happened — and you believe both the discharge and the union's handling were wrong.
The hybrid case is the one individual employees bring, and it is much harder than it looks.
Where the right comes from
Express, and remarkably short:
Suits for violation of contracts between an employer and a labor organization … may be brought in any district court.
That sentence did more than create jurisdiction. In Textile Workers Union v. Lincoln Mills the Supreme Court held it authorises federal courts to fashion a federal common law of collective bargaining agreements — which is why labour contract law is federal, and why it preempts state-law claims that depend on interpreting the agreement.
The duty of fair representation appears nowhere in the statute. Courts implied it from the union's exclusive right to represent everyone in the bargaining unit: with exclusive power comes an obligation to use it in good faith.
What a plaintiff has to prove — and why the hybrid needs both halves
Straight § 301: an agreement, and its breach.
Hybrid § 301: two things, and both are required.
- The employer breached the collective bargaining agreement.
- The union breached its duty of fair representation — conduct that was arbitrary, discriminatory, or in bad faith. Mere negligence, or a judgment call that turned out badly, does not suffice.
Why both? Because the grievance procedure produced an outcome, and that outcome is final and binding on the employee unless the union's breach undermined it. The two claims are, in the Court's phrase, "inextricably interdependent." An employee who proves an unjust firing but cannot show the union failed them loses to both defendants — the arbitration result stands.
This is the single hardest feature of the claim, and the reason most hybrid suits fail.
How long you have to file
Six months for the hybrid claim, borrowed from the unfair-labour-practice provision of the National Labor Relations Act. That comes from DelCostello v. International Brotherhood of Teamsters, which rejected borrowing a state period because the federal labour interest in prompt resolution was closer at hand.
It accrues when the employee knew or should have known of the union's final action — usually the final grievance denial or the decision not to arbitrate.
Six months is brutally short. An employee who spends a few months trying to get answers from the union can be time-barred before understanding there was a claim.
But straight § 301 suits are different. Contract actions between a union and an employer borrow the most analogous state limitations period — often several years. Suits to compel arbitration or vacate an award likewise borrow state law.
This split is the rule secondary sources most often get wrong. Many treat "§ 301" as uniformly six months. It is not. Identify which kind of suit you have first.
What has to happen before you file
Exhaust the grievance and arbitration machinery in the collective bargaining agreement. An employee cannot bypass the contract's own dispute process and go straight to court.
Two exceptions matter:
- The union's breach caused the failure to exhaust — which is exactly what the hybrid claim alleges, so this exception is built into the theory.
- Resort would be futile.
Character: mandatory, subject to those exceptions, not jurisdictional.
Who can be sued — and who cannot
Straight § 301: the union and the employer, as institutions.
Hybrid: both the employer and the union. You may name both, and you must prove both breaches regardless of which one you would rather collect from.
Individual union officers are generally not personally liable for money damages on a § 301 judgment against the union. The statute channels liability to the organisation.
Common defenses
The six-month bar, for hybrid claims — the most effective defense there is.
No breach of the duty of fair representation — the union exercised judgment, even poor judgment, without arbitrariness, discrimination, or bad faith.
Failure to exhaust the contractual grievance procedure.
Finality of the arbitration award.
Preemption, used offensively: where a state-law claim requires interpreting the collective bargaining agreement, § 301 preempts it. Employers use this to remove state cases to federal court and then argue they are time-barred under the six-month rule.
What the claim pays
Back pay, reinstatement, and contract damages, apportioned between the two defendants: the employer is liable for the damages flowing from the breach, and the union for the increase in damages caused by its own breach — typically the wages lost because the grievance was not pursued promptly.
No punitive damages against a union for a breach of the duty of fair representation.
A jury is available for legal relief.
Fees follow the ordinary American rule; there is no fee-shifting provision in the statute.
What people get wrong
"All § 301 suits have a six-month deadline." No. Only the hybrid duty-of-fair-representation claim. Straight contract suits borrow a state period.
"I can sue my employer without suing the union." You may name only the employer — but you still have to prove the union's breach, or the arbitration outcome stands.
"The union made a mistake, so it breached its duty." Negligence is not enough. The conduct must be arbitrary, discriminatory, or in bad faith.
"I'll sue for wrongful termination under state law instead." If the claim requires interpreting the agreement, § 301 preempts it — and you land back on the six-month clock.
"The clock runs from when I was fired." It runs from when you knew or should have known of the union's final action.
"I can sue the union rep personally." Generally not.
Where it came from
Section 301 came in with the Taft-Hartley Act of 1947, at a moment when Congress wanted collective bargaining agreements to be enforceable in court rather than only through economic pressure.
Lincoln Mills in 1957 turned that jurisdictional sentence into a mandate to build a federal common law of labour contracts — one of the more consequential acts of judicial lawmaking in the field, and the source of § 301's broad preemptive effect.
The duty of fair representation arrived on a parallel track, implied from the union's exclusive representation authority. DelCostello in 1983 fixed the hybrid claim's six-month period, reasoning that a claim so close to an unfair labour practice should borrow that statute's clock rather than a state contract period.
The doctrine has been stable since. What changes is how strictly courts police the six months.
Common questions
How long do I have to sue my employer and my union?
Six months for a hybrid claim, running from when you knew or should have known of the union's final action on your grievance. That is far shorter than most employment deadlines.
Does the six-month deadline apply to every section 301 case?
No, and this is the most commonly misstated rule in the area. It governs hybrid duty-of-fair- representation claims. Straight contract suits between a union and an employer borrow the most analogous state limitations period.
Do I have to prove my union did something wrong?
Yes, even if you only want to recover from the employer. Without proof of the union's breach, the grievance outcome is final and binding on you.
What counts as a breach of the duty of fair representation?
Conduct that is arbitrary, discriminatory, or in bad faith. Ordinary negligence or a losing judgment call does not meet the standard.
Can I sue in state court for wrongful termination instead?
Usually not. If the claim requires interpreting the collective bargaining agreement, § 301 preempts it, the case can be removed to federal court, and the six-month clock applies.