In his concurring opinion, Justice John Paul Stevens wrote that while he agreed with the Court’s decision that the commission’s prohibition violated the First Amendment, he did not want to weigh in on whether or not the Central Hudson Test adequately protected commercial speech. Stevens also noted that one of the definitions of commercial speech used by the Court, which defined it as “expression related solely to the economic interests of the speaker and its audience,” was far too broad for him to agree with. Stevens concluded with a narrow view of commercial speech, explaining that while it is “afforded less constitutional protection than other forms of speech, [and] it is important that the commercial speech concept not be defined too broadly lest speech deserving of greater constitutional protection be inadvertently suppressed.”

Concurring Opinion by Justice Blackmun

Joined by Justice William Brennan, Justice Harry Blackmun wrote in his concurring opinion that while he agreed with the majority that the commission’s prohibition was too broad, he disagreed with their establishment of the Central Hudson Test as a rule of general applicability. He wrote that “the Court's four-part test is the proper one to be applied when a State seeks to suppress information about a product in order to manipulate a private economic decision that the State cannot or has not regulated or outlawed directly.” Blackmun, however, believed that applying this theory generally to commercial speech would be too restrictive.

Blackmun recognized the legitimate goal of promoting energy conservation on a local and national level, but found the prohibition on advertising to be too broad. Blackmun explained that “[p]ermissible restraints on commercial speech have been limited to measures designed to protect consumers from fraudulent, misleading, or coercive sales techniques. Those designed to deprive consumers of information about products or services that are legally offered for sale consistently have been invalidated.” He emphasized the idea that the government may only interfere in speech in the face of a clear and present danger, writing that absent such conditions, “government has no power to restrict expression because of the effect its message is likely to have on the public.”

In his brief concurrence, Justice William Brennan noted that one of the challenges in this case was determining the specific intent and scope of the commission’s advertising policy. He wrote that “I find it impossible to determine on the present record whether the Commission's ban on all ‘promotional’ advertising, in contrast to ‘institutional and informational’ advertising is intended to encompass more than ‘commercial speech.’ I am inclined to think that Justice Stevens is correct that the Commission's order prohibits more than mere proposals to engage in certain kinds of commercial transactions.” Blackmun concluded that the commission’s policy was unconstitutional under the First Amendment and agreed with Justice Blackmun’s assertion that "[n]o differences between commercial speech and other protected speech justify suppression of commercial speech in order to influence public conduct through manipulation of the availability of information.”