Michigan's Blood Alcohol Limits: 0.08, 0.17, 0.04 and 0.02

Michigan's general limit is 0.08: a person commits OWI by operating a vehicle with an alcohol content of 0.08 grams or more per 100 milliliters of blood, per 210 liters of breath, or per 67 milliliters of urine.^[1] Three other numbers also matter: 0.17 for the high BAC tier, 0.04 for commercial motor vehicles, and 0.02 for drivers under 21.^[1][4][5]

The four numbers at a glance

Concentration	Who it applies to	What it triggers
0.08 or more	Any driver of a vehicle in a place covered by the statute, licensed or not.[8][1]	OWI under MCL 257.625(1)(b); a first offense is punishable by one or more of up to 93 days in jail, a $100 to $500 fine and up to 360 hours of community service.[9]
0.17 or more	Any driver.[1]	High BAC OWI under 625(1)(c): up to 180 days and $200 to $700 for a first offense, a mandatory treatment program of at least one year, and a one-year license suspension.[2][10][3]
0.04 to under 0.08	A person operating a commercial motor vehicle.[4]	A misdemeanor under MCL 257.625m with up to 93 days and a fine of up to $300 for a first offense.[11]
0.02 to under 0.08, or any alcohol from drinking	A driver under 21.[5]	The zero-tolerance offense under 625(6): for a first offense, a misdemeanor punishable by up to 360 hours of community service, a fine of up to $250, or both, with no jail.[12]

Each tier has its own guide: high BAC, commercial vehicles and the under-21 law.

What the units mean

The statute states every limit three ways, depending on what was tested: grams of alcohol per 100 milliliters of blood, per 210 liters of breath, or per 67 milliliters of urine.^[1] The administrative rules for laboratories say blood results are expressed as grams per 100 milliliters, and that serum or plasma results must be converted to a whole-blood equivalent.^[13] Breath results are expressed in grams per 210 liters and truncated to the second decimal place, or to three decimals on instruments set up to report them.^[14]

"BAC" (blood alcohol content) is the everyday shorthand. The jury instructions speak of "bodily alcohol content" or "bodily alcohol level," which covers breath and urine as well as blood.^[15][16]

Being at or over the number is the offense

The 0.08 and 0.17 tiers are "per se" offenses. If the jury finds the alcohol content was at or above the line, it may convict "whether or not this alcohol content affected" the person's ability to drive.^[15] The question is the level at the time of driving. A chemical test result is presumed by statute to be the same as at the time the person operated the vehicle, and jurors are told they may infer that, may weigh the test as they think it deserves, and may consider evidence of drinking after driving.^[17][18] See rising BAC and the time-of-driving question.

Below the number is not automatically legal

A result under 0.08 rules out only the per se theory. A driver can still be charged with OWI for being under the influence, or with operating while visibly impaired, neither of which depends on a number.^[1][6] The chemical-test provisions do not limit any other admissible evidence on these questions.^[19] The guide to what "under the influence" means explains the standard.

Other numbers in the Michigan system

• Temporary permit rule. When an officer takes a license and issues a paper permit, "unlawful alcohol content" means 0.02 or more for a person under 21, 0.04 or more in a commercial vehicle, and 0.08 or more for everyone else.^[20]
• Commercial out-of-service order. Michigan law requires a 24-hour out-of-service order when an officer has reasonable cause to believe a commercial driver had 0.015 or more; having 0.015 is not itself a crime under that section.^[21] Federal rules also bar alcohol use within 4 hours before driving a commercial vehicle.^[22]
• Ignition interlock. The high BAC interlock may come off only after the provider verifies to the Secretary of State that the person drove with no readings at or above 0.025 grams per 210 liters of breath, subject to stated exceptions.^[23]
• Breath test agreement. On a two-decimal instrument, a second breath sample may differ from the first by up to 0.01 when the first result is 0.00 to 0.14, with wider tolerances at higher readings.^[24]
• Medical help. If a breath result is 0.35 or more, the operator must request medical assistance, though failing to do so does not affect the result's validity.^[25]

Boats, snowmobiles and aircraft

The 0.08 standard also applies to operating a motorboat on Michigan waters, but the boating statute has no 0.17 tier.^[26] Snowmobile law uses the same under-the-influence, 0.08 and any-Schedule-1 standards.^[27] For pilots and aircraft crew, Michigan's Aeronautics Code sets a 0.02 limit and forbids operating within 8 hours after drinking.^[28]

The snowmobile and ORV under-21 provisions still contain a stale sentence saying that, beginning October 1, 2018, the under-21 range runs up to 0.10. The Vehicle Code replaced its own date-based rollback in 2021, but those sections were not updated. Do not apply those numbers to car and truck drivers.^[29]

The "sunset" myth: is the limit going back to 0.10?

Many websites say Michigan's 0.08 limit expires on a set date. That was true of older versions of the statute. The 2008 act said 0.10 would apply beginning October 1, 2013, and by the time of 2017 PA 153 the date had been pushed back to October 1, 2021.^[30] Those dates no longer apply.

2021 PA 85, effective September 24, 2021, replaced the fixed date with a trigger. The limit stays 0.08 unless Michigan stops receiving federal highway construction funding conditioned on a national blood alcohol limit, the state treasurer certifies and publishes that fact, and five years then pass.^[7][31] As of October 2026, the 0.08 limit remains in the statute.^[1]

The 0.17 high BAC tier carried no expiration date of its own in the 2008 and 2017 versions, and the current text of MCL 257.625(1)(c) has no sunset.^[30][32] The 0.17 tier appears in 2008 PA 462, which took effect October 31, 2010.^[33]

How the number is measured

Breath, blood and urine testing each follow their own statutory and rule requirements, covered elsewhere in this hub: the roadside preliminary breath test, the station breath test, blood tests and implied consent. Jurors are told to consider whether a test was technically accurate, whether the equipment was maintained and whether the person giving it was trained.^[34]