Although cannabis-related businesses have thrived in the localities that have legalized marijuana as a consumer product, the industry has suffered from crippling uncertainty, in the form of limited access to the banking system. The cannabis industry thus has been forced to operate in a cash-intensive “gray market,” which is a problem. An entire industry conducting all of its business in cash cannot be fairly taxed or regulated and, historically, has been associated with lawlessness—everything from security concerns, transportation and currency problems, money laundering, and cash hoarding. This brief reviews and analyzes the issues that surround marijuana banking and offers several policy options for addressing the tension between federal enforcement and state sovereignty as it related to marijuana banking.