IRVINE, CA—The deep divide between the federal government and a growing number of states when it comes to the matter of marijuana legalization has placed those involved with the housing industry in a very vulnerable position. The issue has become increasingly complex, as little guidance has been handed down on how to comply with contradictory obligations regarding tenant rights and other housing-related matters in an increasing number of states where marijuana has been legalized.

Over the course of nearly two decades, state after state has legalized marijuana for medicinal purposes. In 21 states and the District of Columbia, medical marijuana is legal. And four other states have passed legislation paving the way for certain medical patients to legally use cannabis extracts.

Yet another layer has been added to the marijuana debate, now that two states have legalized pot for recreational use and others are looking to do the same, citing the potential to generate millions in tax revenue. The first two months of legal recreational marijuana sales in Colorado brought in more than $3.8 million in tax revenue. And state-licensed pot retailers say they are on track to collect nearly $100 million in tax annually, which is more than double the nearly $40 million brought in by tax revenue from alcoholic beverages in Colorado in 2013.

In light of increasing marijuana legalization at the state level, 18 members of Congress recently sent a bipartisan letter to President Barack Obama asking him to have pot dropped from its current Schedule 1 drug classification. However, the federal government does not seem likely to legalize marijuana anytime soon.

Thus, allowing marijuana on their premises puts residential property owners at risk of penalties from the federal government, such as losing their buildings via civil forfeiture cases. On the other hand, if they decide to ban pot use in states where marijuana is legal, these property owners could find themselves threatened with legal action – and a storm of negative publicity.

These risks are exemplified by the fallout from a Washington landlord's response after pot use was decriminalized in the state. All tenants in the landlord's 171-unit building were asked to sign a lease addendum stating that any use or possession of marijuana would give grounds for eviction. One building occupant is a medical marijuana patient who uses a liquid form of pot. He went to the press with his story, which resulted in an attorney's offer to represent him pro bono and prompted the management company to issue a statement that they were unaware of this tenant's need of a medical marijuana tincture and had only been trying to create a smoke-free environment.

Lawmakers in at least one state where medical marijuana is legal are working to provide some protection for residential property owners who decide to prohibit pot on their premises. The Michigan State Senate passed Senate Bill 783 earlier this year, which would allow private property owners to include a ban against smoking or cultivating marijuana in residential leases. The bill is currently pending in the Michigan House of Representatives. In the meantime, marijuana-related tenant issues remain a concern for landlords in Michigan – and beyond.

For landlords who receive federal housing subsidies, the medical marijuana maze is arguably even more difficult to navigate. In Colorado, a tenant recently challenged a local housing authority's zero tolerance policy regarding both medical and recreational marijuana – and won. The agency had decided to terminate the tenant's housing assistance after realizing that she is a medical marijuana patient. Her lawyer met with representation for the U.S. Department of Housing and Urban Development (HUD), who reiterated an earlier stance that HUD would leave the decision to take away a medical marijuana user's housing benefits up to local housing authorities, despite its position that it can not allow disabled clients to use medical marijuana. The tenant's lawyer then met with the local housing authority, which amended its policy so that marijuana-related tenant issues will now be reviewed on a case-by-case basis.

Homeowners' associations are also beginning to realize how complex the issue of legalized marijuana can be. An HOA board in Arizona voted to ban subdivision residents from smoking pot in their yards and on their patios recently, though medical marijuana is legal in the state. Various homeowners spoke out against the ban to the press and within days of the news coverage, the HOA board lifted the restrictions on medical marijuana in the community. 

All those involved with the housing industry need to tread carefully when it comes to marijuana-related issues, as rules and regulations governing its use continue to evolve in states around the country. Since no clear resolution is in sight when it comes to the conflict between state and federal laws, residential property owners need to be as informed as possible about fair housing implications, tenant disputes and other matters related to current marijuana legislation in their areas.

Morgan Stewart is a partner with Manly, Stewart & Finaldi based in Irvine, CA. The views expressed in this column are the author's own.