The long-standing preemption doctrine allows Congress to preempt, or usurp, state law by means of a federal statute. With 33 states and the District of Columbia having enacted medical marijuana laws, which permit individuals with serious health conditions to legally use marijuana, courts in recent years have repeatedly been called on to determine whether these state statutes are preempted by the federal Controlled Substances Act, 21 U.S.C. ¶ 801 et seq., or CSA. The CSA, enacted 50 years ago, makes possession or sale of marijuana illegal, and at first blush would appear to preempt state laws permitting its use. Whether this is the case, however, is far from certain.

Preemption is grounded in the Supremacy Clause in the U.S. Constitution, which provides that "the Laws of the United States … shall be the Supreme Law of the Land … any Thing in the … Laws of any State to the Contrary notwithstanding." U.S. Const. Art. VI, cl. 2. Under the doctrine of "field preemption," a federal statute may preempt state law implicitly where it is clear that Congress sought to occupy an entire regulatory field. Other forms of preemption are "obstacle preemption" (a state law is preempted if it stands as an obstacle to the objectives of Congress) and "impossibility preemption" (simultaneous compliance with both state and federal law is impossible). Employers and others who have argued that the CSA preempts state medical marijuana statutes have relied primarily on the latter two types of preemption, sometimes collectively referred to as conflict preemption.

In fact, the preemption doctrine is a far more limited one than many attorneys have suggested. In Wyeth v. Levine, 555 U.S. 555, 565 (2009), the Supreme Court held that a federal law will not preempt state law claims unless Congress expressed a "clear and manifest" intent that it do so. Moreover, obstacle preemption—a doctrine frequently employed in cases where a state medical marijuana law is at issue—only invalidates state statutes when they pose an actual conflict with an overriding federal purpose and objective. Such a conflict must be a clear-cut one, and preemption will not apply other than where "the repugnance or conflict is so direct and positive that the [federal and state laws] cannot be reconciled or consistently stand together." In re MTBE Products Liab. Litig, 725 F. 3d 65, 102 (2d Cir. 2013).

Drug Testing Cases

For several decades after the earliest drug testing cases in California involving medical marijuana patients in the 1990s, preemption was an effective argument for employers whose termination of legal cannabis users after drug tests was challenged in court. One of the best-known cases where a court found for an employer based on preemption is Emerald Steel Fabricators v. Bureau of Labor & Industry, 230 P.3d 518 (Ore. 2010). In Emerald Steel, the Oregon Supreme Court relied on obstacle preemption and held that the CSA preempted Oregon's medical marijuana statute because its purpose was to criminalize and prohibit all "Schedule I" drugs, a category that includes marijuana. Thus, reasoned the court, the CSA preempts all state statutes that affirmatively authorize the use of medical marijuana. During the next seven years, the numerous decisions finding that the CSA preempted state cannabis statutes frequently cited Emerald Steel.

As more states during the last decade passed medical marijuana laws, anti-discrimination provisions in these statutes barring adverse action against employees enrolled in a state cannabis medical program based on their marijuana use became more prevalent, and nine states—including New York—now have them. Such provisions have proven to be a useful vehicle for defeating preemption arguments in medical marijuana drug test cases.

A decision from the U.S. District Court in Connecticut, Noffsinger v. SSC Niantic Operating Co., 273 F. Supp. 3d 326 (D. Conn. 2017), which included a detailed analysis of the preemption doctrine and the extent to which it applies to state medical marijuana laws, has had a major impact on preemption's validity in medical marijuana cases. The issue before the Noffsinger court was whether the CSA bars the enforcement of a Connecticut medical cannabis law prohibiting discrimination against employees who use marijuana for medical purposes. After assessing the history and purpose of obstacle preemption, the court focused on the fact that the CSA "does not make it illegal to employ a marijuana user. Nor does it purport to regulate employment practices in any manner." Id. at 334.

Distinguishing between Connecticut's Palliative Use of Marijuana Act (PUMA) and other states' medical cannabis statutes that do not contain anti-discrimination provisions, the Noffsinger court found that no clear conflict exists between the CSA and PUMA, and that PUMA does not represent an obstacle to the objectives of the CSA. Since Noffsinger, other courts have adopted this approach and found no preemption in medical marijuana cases.

One such case, from the Delaware Superior Court, is Chance v. Kraft Heinz Foods Co., 2018 Del. Super. LEXIS 1773 (Del. Super. Ct. Dec. 17, 2018). The court in Chance directly addressed the question of whether Delaware's medical marijuana law was preempted by the CSA, and concluded that it was not. Chance considered the issue both from the perspective of obstacle preemption and also in terms of whether there is a positive conflict between the CSA and the state cannabis statute. Echoing Noffsinger, the Chance court pointed out that because the CSA "does not make it illegal to employ someone who uses marijuana" and does not attempt to regulate this field, no conflict preemption exists. Similar reasoning was employed by the Rhode Island Superior Court, which found no preemption in Callaghan v. Darlington Fabrics Corp., 2017 R.I. Super. LEXIS 88 (R.I. Super. May 23, 2017).

Workers' Compensation

The interplay between preemption and medical marijuana has also arisen in worker's compensation cases. For example, in 2018 the Maine Supreme Court in Bourgoin v. Twin Rivers Paper Co., 2018 ME 77, held that a worker's compensation board order directing an employer to pay the costs of medical marijuana treatment for an injured employee was invalid because the order was preempted by the CSA. In Bourgoin, the court reasoned that compliance with both the worker's compensation board order and the CSA was not feasible under impossibility preemption.

Bourgoin, however, may not represent the majority view. The Appellate Division of the New Jersey Superior Court in early 2020 reached the opposite conclusion in Hager v. MSK Construction Co., 2020 N.J. Super. LEXIS 4, as have several New Mexico courts. In Hager, the employer argued that the state could not order it to pay for an employee's medical treatment that involved the use of medical cannabis because of the impossibility of complying with both the CSA and the state order. The Hager court, however, ruled that while the possession and distribution of marijuana is a criminal offense under the CSA, an employer's reimbursement of a registered medical marijuana patient's use of medical cannabis does not involve committing those offenses. In other words, the workers' compensation order does not compel an employer to possess or distribute cannabis, and those are the acts—not merely reimbursing an employee for the cost of medical marijuana—that are unlawful under the CSA.

Conclusion

Preemption was an effective and usually winning argument in medical marijuana cases for many years because the question courts confronted was whether the CSA preempted a state statute that allowed the use of medical marijuana. Framed that way, courts generally had little difficulty concluding that conflict preemption was applicable. More recently, at least in cases involving medical marijuana laws with anti-discrimination provisions, the question is quite different. In Noffsinger and cases following it the issue has been whether the CSA preempts a state law prohibiting employment discrimination against an employee on the basis of that individual's use of state-authorized medicinal marijuana. That conflict preemption applies in these circumstances is a far less persuasive argument.

Courts' analyses of when preemption applies in medical marijuana cases has been valuable in the sense that it has emphasized and focused attention on the limits of the preemption doctrine. In today's climate, at least in the area of cannabis law jurisprudence, courts arguably are less inclined to apply the preemption doctrine in a sweeping fashion whenever a state statute seems inconsistent with a federal law. Instead, they may well apply the more nuanced analysis that the District of Connecticut and other courts have recently engaged in and determine that the reach of preemption is not so long as once had been assumed.

Geoffrey Mort is of counsel to Kraus & Zuchlewski.