The short answer
Bring a photo ID that a government issued, and cash. Where the only licensed cannabis store is a medical one, check that state's page for what its program asks you to show. Many stores take nothing but cash. A store that does accept a debit card can stop accepting it without notice.
The detail
A driver's license, a state ID card, a passport and a military ID are the ones stores accept most often. Each of them carries your photograph and your date of birth. Most stores will not accept a photograph of your ID on a phone, so bring the card itself. Where the state issues a medical card, the store checks the name on it against the name on your ID.
Federal drug law is the reason for the cash. Marijuana is listed in schedule I of the federal drug schedules, apart from two categories a final rule of April 28, 2026 moved to schedule III (21 U.S.C. § 812. Schedules of controlled substances, Schedules of Controlled Substances: Rescheduling of Food and Drug Administration Approved Products Containing Marijuana From Schedule I to Schedule III; Corresponding Change to Permit Requirements, 91 FR 22714 (Apr. 28, 2026)). Distributing a controlled substance is a federal offense except where federal drug law authorizes it (21 U.S.C. § 841. Prohibited acts A).
A bank or a card company decides for itself whether to serve a business federal law still reaches. A store that no bank or card company will serve keeps a cash machine inside instead. Where a store does take a debit card, it may run the payment through a cashless ATM terminal, which charges its own fee and debits a rounded-up amount, with the difference handed back in cash.
What varies by state
The state you are buying in decides how old you have to be, and whether you need a card as well as an ID. Do I need a medical card to buy weed in my state? sorts all fifty-one into groups and links each one. In the 20 states and districts whose only licensed cannabis store is a medical one, each state's page says what that program asks a buyer to hold. Most issue a card. A few work from a practitioner's recommendation or a prescription in a state registry.
Open the page for the state you are buying in from cannabis law, state by state. It names the minimum age and what the medical program asks for, with the statute behind each one, or says so where that state's own text could not be read.
What a store takes in payment is that store's own arrangement, and no state page carries it. Two stores in the same city can differ.
What to watch out for
Bring more cash than the menu price. The price on the menu may not include tax, so the total at the counter can be higher. A cash machine inside the store charges a fee on top of that.
Most stores refuse an expired ID, so check the date on yours before you leave home. A store refuses an expired medical card too.
Where to go next
The store directory holds a page for each location this site has an active record for. A store page says what you need in order to buy there, and gives the date the record was last checked. Open the page for the store you plan to visit before you go.
Cannabis law, state by state is where the age rule and the card requirement for your state are kept, each with the law behind it.
What happens the first time I buy at a dispensary? takes it from the door to the counter, once you have what you need to get in.