Michigan’s THC limits work on three tracks. If you’re 21 or older, you can carry up to 2.5 ounces of marijuana in public and keep up to 10 ounces at home. Commercial edibles cap at 10 milligrams of THC per serving and 200 milligrams per package. And if you’re driving without a medical marijuana card, the limit is zero: any detectable THC in your blood is a violation. Penalties climb from a $500 civil ticket for modest overages to misdemeanor charges for driving, with federal law adding its own layer the moment you cross a state line.1Michigan Legislature. Michigan Regulation and Taxation of Marihuana Act (Initiated Law 1 of 2018)
How Much You Can Legally Possess
For adults 21 and older, the Michigan Regulation and Taxation of Marihuana Act sets these limits:
- Up to 2.5 ounces of marijuana in public, of which no more than 15 grams may be in concentrate form.
- Up to 10 ounces at home, with anything above 2.5 ounces stored in a locked container or secured area.
- Up to 12 plants per household for personal cultivation.
The 2.5-ounce public cap applies to what you physically have on you, not separate stashes distributed across pockets or bags. The 12-plant limit is per residence, so two adults living together share that cap rather than doubling it. Concentrates are tracked separately because they pack far more THC per gram than flower.1Michigan Legislature. Michigan Regulation and Taxation of Marihuana Act (Initiated Law 1 of 2018)
Registered medical marijuana patients operate under the Michigan Medical Marihuana Act instead. A patient with a valid registry card can possess up to 2.5 ounces of usable marijuana and, if growing at home, keep up to 12 plants in an enclosed, locked facility without risk of arrest or prosecution.2Michigan Legislature. Michigan Code MCL 333.26424 – Protections for the Medical Use of Marihuana
Potency Limits on Commercial Products
Michigan’s Cannabis Regulatory Agency sets THC concentration ceilings for products sold at licensed dispensaries. Recreational edibles are limited to 10 milligrams of THC per serving and 200 milligrams per package, with a 10 percent variance permitted in either direction. Licensed processors must test each batch, and the label must reflect actual laboratory results.
Packaging matters too. All commercially sold cannabis products must meet child-resistant packaging standards, and edibles specifically require packaging that stays child-resistant across its useful life, not just on first opening.
These product rules apply to what licensed businesses sell. They don’t govern what you grow, cook, or process at home for personal use.
Penalties for Going Over Possession Limits
Michigan’s penalty structure scales with how far past the limit you go. The dividing line is roughly double the legal amount.
Up to Twice the Limit
Carrying up to 5 ounces in public, or growing up to 24 plants, is a civil infraction on a first offense rather than a criminal charge. The fine is capped at $500, and the excess marijuana is confiscated. A second violation of the same kind carries the same $500 ceiling.1Michigan Legislature. Michigan Regulation and Taxation of Marihuana Act (Initiated Law 1 of 2018)
More Than Twice the Limit
Going beyond double, meaning more than 5 ounces in public or more than 24 plants, is a misdemeanor. The MRTMA includes an unusual protection: no jail sentence for this misdemeanor unless the violation was habitual, willful, and for a commercial purpose, or involved violence. Most people caught with somewhat-over-double amounts see fines and forfeiture rather than incarceration.3Michigan Legislature. Michigan Code MCL 333.27965 – Penalties
Unlicensed commercial distribution is a different matter. Selling marijuana without a license, or distributing quantities well beyond personal use, can trigger charges under Michigan’s broader drug laws outside the MRTMA, which carry potential felony penalties including significant prison time. The MRTMA’s softer penalty tiers protect personal overages and unpaid transfers to other adults, not sales.
Under 21
Anyone under 21 caught with up to 2.5 ounces or up to 12 plants faces a civil infraction, not a criminal charge. For a first violation, the fine is up to $100, plus forfeiture; those under 18 also face community service and four hours of mandatory drug education or counseling. A second violation raises the fine ceiling to $500 and doubles the education requirement for minors to eight hours.3Michigan Legislature. Michigan Code MCL 333.27965 – Penalties
The Zero-Tolerance Limit for Driving
This is where Michigan’s THC rules bite hardest. Under the Michigan Vehicle Code, it is illegal to drive with any detectable amount of a Schedule 1 controlled substance in your body, and marijuana remains on that list for driving purposes. You don’t have to be visibly impaired. Any amount of THC on a blood test supports a charge.4Michigan Legislature. Michigan Code MCL 257.625 – Operating Under the Influence
THC can remain detectable in blood for days or weeks after use, so the zero-tolerance rule reaches people who consumed marijuana long before driving and are completely sober behind the wheel. For regular cannabis users, this is the single most consequential THC limit in Michigan law.
First-Offense OWI Penalties
A first-offense conviction for driving with any amount of THC is a misdemeanor. Penalties can include:
- Up to 93 days in jail.
- A fine of $100 to $500.
- Up to 360 hours of community service.
- License suspension of up to 180 days, plus 6 points on your driving record.
A court can also order an ignition interlock device as a probation condition.4Michigan Legislature. Michigan Code MCL 257.625 – Operating Under the Influence5Michigan State Police. Impaired Driving Law
The Medical Marijuana Exception
Registered patients get a meaningful carve-out. In People v. Koon (2013), the Michigan Supreme Court held that the Medical Marihuana Act’s protections override the Vehicle Code’s zero-tolerance rule for cardholders. A patient with a valid registry card can drive with detectable THC in their system as long as they are not actually impaired, and the prosecution must prove impairment rather than mere presence.6Michigan Courts. Operating a Motor Vehicle
For everyone else, presence is enough. If you’re a recreational user without a medical card, any detectable THC in a blood draw after a traffic stop can support an OWI charge.
How Officers Test
When an officer suspects drug impairment, a stop typically begins with field sobriety tests. If those suggest impairment, the officer can request a blood draw, and the blood test is the primary evidence used in court because it measures actual THC concentration. Michigan has also been piloting roadside oral fluid (saliva) screening. Oral fluid results themselves are not evidence at trial; they function like a preliminary breath test, supporting probable cause for the blood draw that follows.7NCOIL. Roadside Oral Fluid Screening to Detect Impairment
Delta-8 and Hemp-Derived THC
Michigan classifies delta-8 THC as marijuana and regulates it under the same framework as delta-9. Since October 2021, selling delta-8 products without a Cannabis Regulatory Agency license has been illegal in the state. Delta-8 gummies, vapes, and tinctures sold at gas stations or convenience stores without CRA licensing violate Michigan law regardless of whether they were made from hemp.8Michigan Cannabis Regulatory Agency. Delta-8 Information
The 2018 federal Farm Bill removed hemp (cannabis with no more than 0.3 percent delta-9 THC by dry weight) from the Controlled Substances Act, creating a national loophole some manufacturers use to produce high-potency delta-8 from hemp. Michigan closed that loophole at the state level. If you buy delta-8 in Michigan, it should come from a licensed dispensary.
Federal Law Still Applies in Some Places
Michigan’s limits stop at the state line and at the boundary of federal property. Marijuana remains a Schedule I controlled substance under federal law, and two situations catch Michigan residents regularly.
Crossing any state line with marijuana is a federal offense, even between two states that have legalized it. Federal simple-possession penalties start at up to one year in prison and a minimum $1,000 fine for a first offense, with mandatory minimums of 15 days on a second offense and 90 days on a third.9Office of the Law Revision Counsel. 21 USC 844 – Penalties for Simple Possession
National parks, military installations, federal courthouses, and other federal property in Michigan are governed by federal law, not the MRTMA. Possession there can result in federal charges regardless of your Michigan rights. TSA officers don’t hunt for marijuana at security checkpoints, but if they find it during screening they are required to refer the matter to law enforcement, and any product above 0.3 percent delta-9 THC remains prohibited for air travel even on flights entirely within Michigan.10Transportation Security Administration. Complete List (Alphabetical)