Following up on my earlier coverage of the 10th Circuit's opinion citing Citizens United v. Federal Election Commission, the 3d Circuit has concluded that Citizens United  does not compel a finding that a for-profit corporation can exercise religion. Here are excerpts from the majority's opinion (at Part IV.A):

Citizens United is thus grounded in the notion that the Court has a long history of protecting corporations' rights to free speech. 

... 

We must consider the history of the Free Exercise Clause and determine whether there is a similar history of courts providing free exercise protection to corporations. We conclude that there is not. In fact, we are not aware of any case preceding the commencement of litigation about the Mandate, in which a for-profit, secular corporation was itself found to have free exercise rights. Such a total absence of caselaw takes on even greater significance when compared to the extensive list of Supreme Court cases addressing the free speech rights of corporations.

(I interject here to remark that this line of reasoning does not strike me as terribly persuasive. First, there are numerous instances in which the absence of judicial precedent is not a justification for rejecting the argument of the parties. This distinction strikes me as too narrow a reading of Citizens United . It may be that the two are distinguishable, but absence of precedent is not among them. Second, by asserting that the corporation is "secular," it's hard to get around the conclusion that the majority opinion has, in circular fashion, presumed the conclusion.)

We are unable to determine that the "nature, history, and purpose" of the Free Exercise Clause supports the conclusion that for-profit, secular corporations are protected under this particular constitutional provision. Even if we were to disregard the lack of historical recognition of the right, we simply cannot understand how a for-profit, secular corporation--apart from its owners--can exercise religion. . . .

In urging us to hold that for-profit, secular corporations can exercise religion, Appellants, as well as the dissent, cite to cases in which courts have ruled in favor of free exercise claims advanced by religious organizations. See, e.g. , Gonzalez v. O Centro Espirita Beneficente Uniao Do Vegetal ; Church of the Lukumi Babalu Aye, Inc. v. Hialeah . None of the cases relied on by the dissent involve secular, for-profit corporations. We will not draw the conclusion that, just because courts have recognized the free exercise rights of churches and other religious entities, it necessarily follows that for-profit secular corporations can exercise religion. As the Supreme Court recently noted, "the text of the First Amendment . . . give es special solicitude to the rights of religious organizations." Hosanna-Tabor Evangelical Lutheran Church & Sch. v. EEOC . That churches--as means by which individuals practice religion--have long enjoyed the protections of the Free Exercise Clause is not determinative of the question of whether for-profit, secular corporations should be granted these same protections.

(some citations omitted) 

(I interject again with two problematic point in this reasoning. First, the majority concludes that even though courts have recognized X, "[w]e will not draw the conclusion" that "it necessarily follows" that the courts will recognize Y. That may be true, but that does not explain why the two should be treated differently--except, as noted earlier, courts haven't done so previously, which is just restating a fact and is not a justification. Second, the majority does not claim that "churches" exercise religion, but that "churches" are a "means by which individuals practice religion"; but, in the paragraph before that, it claims that it "cannot understand how a for-profit, secular corporation--apart from its owners--can exercise religion." The distinction between whether members of a corporate form, whether a church or a for-profit corporation, can exercise religion within that corporate form is not readily explained in the majority's opinion, except that the church is the more common form for the exercise of religion.)

Since Conestoga is distinct from the Hahns, the Mandate does not actually require the Hahns to do anything. All responsibility for complying with the Mandate falls on Conestoga. Conestoga "is a closely-held, family-owned firm, and [we] suspect there is a natural inclination for the owners of such companies to elide the distinction between themselves and the companies they own." But, it is Conestoga that must provide the funds to comply with the Mandate—not the Hahns. We recognize that, as the sole shareholders of Conestoga, ultimately the corporation‘s profits will flow to the Hahns. But, "[t]he owners of an LLC or corporation, even a closely-held one, have an obligation to respect the corporate form, on pain of losing the benefits of that form should they fail to do so." "The fact that one person owns all of the stock does not make him and the corporation one and the same person, nor does he thereby become the owner of all the property of the corporation." The Hahn family chose to incorporate and conduct business through Conestoga, thereby obtaining both the advantages and disadvantages of the corporate form. We simply cannot ignore the distinction between Conestoga and the Hahns. We hold . . . that the free exercise claims of a company‘s owners cannot "pass through" to the corporation.

 (citations omitted)

(This holding is expressly contrary to the logic--but, admittedly, not the holding--articulated in Citizens United , where the majority concluded that the regulation, if allowed, "would permit Government to ban political speech simply because the speaker is an association that has taken on the corporate form.") 

There are other excerpts, and a dissenting opinion addressing the matter, if you're interested in reading the whole 96-page opinion.