Eighth Circuit Holds ERISA Preempts Arkansas’s Geographic Pharmacy Network Adequacy Requirements, Affirming Dismissal of Plan Participant’s Unjust Enrichment Class Action

In Flowers v. Caremark PCS Health, LLC, No. 25-3068, — F.4th —-, 2026 WL 1859929 (8th Cir. June 29, 2026), the Eighth Circuit held that ERISA preempts Arkansas’s geographic pharmacy network adequacy requirements and affirmed the dismissal of a plan participant’s unjust enrichment class action. Plaintiff, a participant in an ERISA-governed employee benefits plan, sued Caremark PCS Health, LLC and CaremarkPCS Pennsylvania Mail Pharmacy, LLC (collectively, “Caremark”), the pharmacy benefits manager (“PBM”) administering his prescription drug benefit. Plaintiff alleged that Caremark unjustly enriched itself by covering plan members’ maintenance prescriptions only if filled at CVS retail pharmacies or through mail order, in violation of two Arkansas statutes: the Mail Order Provision, Ark. Code Ann. § 17-92-119(b)(2), and the Network Adequacy Provision, Ark. Code Ann. § 23-92-505(a)(1)(A). The district court granted Caremark’s Rule 12(b)(6) motion to dismiss, and the Eighth Circuit affirmed.

Reviewing the dismissal de novo, the court first rejected Plaintiff’s Mail Order Provision claim. That provision prohibits PBMs from requiring patients to receive prescriptions through home delivery services. Because Caremark, as alleged, required plan members to fill maintenance prescriptions either by mail or at CVS pharmacies, Plaintiff did not allege facts showing that Caremark required prescriptions to be filled only through home delivery. The court held that Plaintiff therefore failed to plausibly plead a violation of the Mail Order Provision.

Turning to the Network Adequacy Provision, the court explained that the provision requires PBMs to provide a “reasonably adequate and accessible” network but does not define that phrase. Implementing regulations promulgated by Arkansas’s Insurance Commissioner clarify network adequacy through what the court labeled the “Geographic Coverage Requirements,” which mandate that specified minimum percentages of plan members in urban, suburban, and rural areas live within set distances of an in-network retail community pharmacy. The court observed that Plaintiff’s theory rested on alleged violations of these Geographic Coverage Requirements, and that Plaintiff had made no factual allegations regarding the number or location of CVS pharmacies or members’ proximity to them. Because Caremark did not raise this pleading deficiency, the court proceeded to the parties’ primary focus: whether ERISA preempts the Geographic Coverage Requirements.

The court explained that ERISA expressly preempts state laws that “relate to” an employee benefit plan, and that a state law has an impermissible connection with an ERISA plan if it governs a central matter of plan administration, interferes with nationally uniform plan administration, or forces a plan to adopt a particular scheme of substantive coverage. Because PBMs manage benefits on behalf of plans, the court reasoned, regulation of PBMs functions as regulation of the plan itself. Distinguishing its earlier decision in Pharmaceutical Care Management Ass’n v. Wehbi, 18 F.4th 956 (8th Cir. 2021), which upheld North Dakota accreditation provisions that caused only modest disuniformity, the court held that the Geographic Coverage Requirements impose a far greater burden. The requirements force PBMs to tailor and continually retailor their networks, and potentially build new pharmacies, as members relocate, areas change classification, or in-network pharmacies close. The court concluded that these requirements interfere with the nationally uniform plan administration that ERISA was enacted to protect, and that ERISA therefore preempts them, rendering them without effect. Because Plaintiff’s unjust enrichment theory depended on violations of preempted requirements, it did not state a plausible claim, and the court affirmed.