On March 2, 2012, the US Court of Appeals for the District of Columbia Circuit issued an opinion in Comau, Inc. v. NLRB. The key litigated issue was whether an employer unilaterally implemented changes to the terms and conditions of employment on the date that the changes were "reasonably comprehended" by the parties or on the date that the changes became effective.

In 2008, Comau, Inc. began collective bargaining negotiations for a collective bargaining agreement (CBA) with one of the unions representing its employees, the Automated System Workers Local 1123 (ASW), to succeed an expiring CBA. As an interim measure, the parties agreed to extend the terms of the expiring CBA until they finalized a new CBA. The parties agreed that either party could terminate the extension on 14 days notice. Comau wanted its unionized employees to pay a premium for health insurance expenses as did its nonunionized employees. This became the major issue between Comau and the ASW.

The parties exchanged several proposals on the health insurance issue but could not reach agreement on this point. Comau declared impasse on December 3, 2008, and gave notice to the ASW and separately to the ASW members that it intended to:

Between December 8, 2008, and March 20, 2009, the parties continued to hold bargaining sessions where the union proposed alternative health insurance plans, including one that matched the costs demanded by Comau. The parties did not reach an agreement largely because Comau was concerned about lagging costs from transitioning to the union's proposed alternative insurance plan. Meanwhile, on March 1, 2009, Comau's company health insurance plan went into effect. Under the Company Plan, employees represented by the ASW would pay monthly premiums for health care.

Between March and July, 2009, the ASW filed and amended several unfair labor practice (ULP) charges. The second ULP charge, which underlies this case, alleged that Comau bargained in bad faith by unilaterally implementing a new health insurance plan on March 1, 2009, in the absence of a good faith bargaining impasse.

The NLRB Administrative Law Judge (ALJ) ruled that Comau's unilateral implementation of the company health insurance plan was a ULP. The ALJ determined that:

The five member panel (Board) heading the NLRB's judicial functions affirmed the ALJ's decision and adopted his rulings and findings. The Board adopted the view of the ALJ, who concluded that a change in the terms and conditions of employment can only be considered "implemented" for unit employees when:

Comau appealed the Board's decision to the DC Circuit.

The DC Circuit held that a unilateral change is implemented when it is reasonably comprehended and not necessarily when it is effective. It found that:

Accordingly, the court found that Comau lawfully implemented the plan when the parties were at impasse. Therefore, Comau's actions were lawful.

Comau did not deny that the parties were not at impasse on March 1, 2009. Rather, Comau contended that it implemented the Company Plan on December 22, 2008, when the parties were at impasse.

The DC Circuit found that no Board precedent supported the the ALJ and Board's "point of no return" analysis. Furthermore, Board precedent recognizing that unilateral changes were implemented when announced or promised contradicted the Board's decision against Comau. The DC Circuit further reasoned that the "point of no return" analysis would lead to arbitrary results. For example, if Comau promised wage increases at pre-set future intervals, the analysis would suggest that the employer could rescind those promises if bargaining resumed in the interim.

For these reasons, the DC Circuit held that the NLRB acted in an arbitrary and capricious manner, and vacated the NLRB's finding that Comau committed a ULP.

This case clarifies the law on partial impasses. Continued bargaining does not necessarily:

This decision provides guidance to employers about what they should state within declaration of impasse documents and notices of last best offers, so that the Board and federal courts can identify when they implement unilateral changes during a bargaining impasse. This is especially important when the employers cannot fully roll-out the changes immediately.

Conversely, employers that do not intend to implement unilateral changes, perhaps because they unsure whether collective bargaining has in fact reached an impasse, should avoid communicating hypothetical future actions that unions may reasonably comprehend as implementing unilateral changes effective at a later time.