Detroit Cannabis Possession Limits

Last verified: April 2026

The MRTMA Personal-Use Floor

MRTMA created clear personal-possession limits for adults 21 and older. Inside that floor, possession of cannabis is not a crime. Outside that floor, conduct falls back into the controlled-substance framework of Michigan Public Health Code Article 7 (MCL 333.7401, MCL 333.7403).

Public Possession (2.5 oz / 15 g)

An adult 21+ may carry up to 2.5 ounces of cannabis outside the home, with no more than 15 grams of that amount as concentrate. This is more restrictive than New York’s 3 oz / 24 g limit but generous compared to most other adult-use states (compare California’s 28.5 g flower).

At-Home Storage (Up to 10 oz)

An adult 21+ may possess up to 10 ounces at home, with anything above 2.5 ounces stored in a “container or area equipped with locks or other functioning security devices.” The locked-storage requirement is a Detroit-and-Michigan-specific design choice that most other adult-use states do not impose. The locked-storage rule is enforceable: a search that discovers above-2.5-oz quantities not in a locked container can produce a violation even within the personal-possession floor.

Home Cultivation (12 Plants Per Residence)

MRTMA allows up to 12 plants per residence — a household cap, not per-person. So a household with one adult, two adults, three adults, or any larger number is capped at 12 plants total. The cap is significantly more generous than New York’s 6 + 6 (mature + immature) limit. See Home Cultivation.

Sharing (Gifting) — 2.5 oz

An adult 21+ may transfer up to 2.5 ounces to another adult 21+ without remuneration (gifting), so long as the transfer is not advertised or promoted to the public. The “without remuneration” restriction is strict: exchanging cannabis for cash, services, or any other thing of value — even where the cannabis is technically labeled as a “gift” alongside payment for an unrelated “sticker” or T-shirt — constitutes an unlawful sale under MCL 333.7401.

Above the Floor — Penalty Escalation

Possession beyond MRTMA’s caps falls back into Michigan Public Health Code Article 7:

• 2.5 to 5 oz in public — civil infraction with $500 fine for first offense (MCL 333.7403)
• Over 5 oz in public — misdemeanor with up to 93 days in jail and $500 fine
• Larger quantities (former felony thresholds) — still trigger felony exposure
• Sale or delivery without a CRA license (MCL 333.7401) — can be charged as a felony; sales of less than 5 kilograms carry up to 4 years and a $20,000 fine

Public Consumption Restrictions

Public consumption remains illegal in Detroit, including:

• Sidewalks (cannabis use is prohibited in any public place)
• Parks (city, state, federal — including Belle Isle)
• Vehicles (parked or moving; passenger compartment containers must be sealed)
• Sports venues (Comerica Park, Ford Field, Little Caesars Arena, Michigan Stadium)
• K-12 school grounds
• Federal property (Theodore Levin Courthouse, McNamara Federal Building, Detroit Metro Airport, Coast Guard, Detroit-Windsor border crossings)

Transport Within Vehicles

Cannabis in a vehicle must be in a sealed container in the trunk or in a non-passenger area. Open containers in the passenger compartment can be a basis for a traffic-stop search. The smell of burnt cannabis can be a factor in a roadside DUI determination; smell of unburnt cannabis alone is more contested and may not support a vehicle search depending on the jurisdiction. See DUI & the Koon Case.

The Border Question

Possession of cannabis at the Detroit-Windsor border crossings (Ambassador Bridge, Detroit-Windsor Tunnel, planned Gordie Howe International Bridge) is a federal crime regardless of MRTMA. CBP officers can ask about cannabis use; an admission can result in lifetime inadmissibility for non-citizens under INA § 212(a)(2)(A)(i)(II). See Lifetime Inadmissibility.