How the Two Alcohol Counts in a California DUI Case Differ
The 23152a versus 23152b question usually starts with a court complaint that lists two DUI counts for a single drive. That is a common pattern in California. One count says the driver was under the influence of alcohol. The other says the driver had a blood alcohol level of 0.08 percent or more. The same evening supports both, but each count asks the jury a different question.
Knowing that difference helps a person read the complaint, follow the evidence and ask better questions about the case. It also explains why the DMV side of a DUI arrest can move on a separate track.
Sources reviewed in October 2026 include the California Vehicle Code and Penal Code sections on DUI charges and pleading, the CALCRIM criminal jury instructions published by the Judicial Council of California and California DMV guidance.
What the Statute Says About Each Count
Vehicle Code section 23152 lists several separate DUI offenses. Subdivision (a) makes it unlawful for a person who is under the influence of any alcoholic beverage to drive a vehicle. Subdivision (b) makes it unlawful for a person who has 0.08 percent or more, by weight, of alcohol in the blood to drive a vehicle.
The wording looks similar, yet the two offenses work in different ways. The (a) count is about the effect alcohol had on the driver. By contrast, the (b) count is about a number. Prosecutors can file both because one drive can fit both descriptions at once.
How 23152a Versus 23152b Defines Under the Influence
The statute does not define “under the influence” in its own text. Instead, California juries receive a definition in CALCRIM No. 2110, one of the criminal jury instructions the Judicial Council publishes on its California jury instructions page.
Under that instruction, a person is under the influence if alcohol has so impaired the person’s mental or physical abilities that the person can no longer drive with the caution of a sober person, using ordinary care, under similar circumstances. The instruction also tells jurors that the manner of driving alone is not enough to prove impairment, though jurors may weigh it with other evidence.
For that reason, the (a) count often rests on a mix of observations. Typical examples include the reason for the stop, driving pattern, speech, balance, statements and the results of field sobriety tests. The guide to California field sobriety tests covers how those roadside tasks work.
How the 0.08 Count Is Measured
The (b) count turns on a measurement. Section 23152 says percent by weight is based on grams of alcohol per 100 milliliters of blood or grams of alcohol per 210 liters of breath. So a breath result and a blood result both express the same legal standard, even though the samples differ.
Under this count, the prosecution does not have to prove that the driver was impaired. CALCRIM No. 2111 lists the elements as driving a vehicle and having a blood alcohol level of 0.08 percent or more by weight at that time. Driving behavior and field tests may still come up, but the central issue is the alcohol level during the drive.
The Three Hour Rule in 23152a Versus 23152b Cases
Chemical tests happen after driving, often at a station or hospital. Section 23152(b) addresses that gap with a rebuttable presumption. If a chemical test performed within three hours after driving shows 0.08 percent or more, the law presumes the level was 0.08 percent or more at the time of driving.
Rebuttable means the defense may offer evidence against it. CALCRIM No. 2111 puts the rule in permissive terms for jurors. If the person gave the sample within three hours, jurors may, but are not required to, conclude that the level was 0.08 percent or more when the person drove.
Timing therefore carries more weight in the (b) count. A rising alcohol level after the last drink can raise questions about the level at the moment of driving. The article on rising blood alcohol DUI issues explains that argument in more depth.
Why Prosecutors File Both Counts in 23152a Versus 23152b Cases
Penal Code section 954 allows a charging document to state different versions of the same offense in separate counts. It also says the prosecution does not have to choose between them. As a result, a complaint can list both the (a) count and the (b) count for one drive.
Section 954 adds that an acquittal on one count is not an acquittal on any other count. A jury could doubt a test result yet still find impairment from other evidence. Likewise, it could accept the number while finding the observations of impairment weak.
Filing both counts gives the prosecution two routes based on the same facts. For the defense, it means looking at each count’s evidence on its own terms.
Two Counts but One Punishment
Two counts do not mean two sentences for the same act. Penal Code section 654 says the law may punish an act covered by different provisions under either one, but never under more than one.
Section 954 still allows a conviction on any number of the offenses charged. How the court records and sentences the counts in a given case is a question for the lawyers handling it. Many cases also resolve by plea, which can change how the counts end up. The article on a DUI no contest plea covers that route.
How Test Results Shape the Impairment Side of 23152a Versus 23152b
A chemical test still plays a role in the (a) count. Vehicle Code section 23610 creates presumptions in trials under section 23152(a). Below 0.05 percent, the law presumes the person was not under the influence. From 0.05 to under 0.08 percent, no presumption applies either way, though jurors may consider the result with other evidence. At 0.08 percent or more, the law presumes the person was under the influence.
Section 23610(c) adds that these presumptions do not limit the introduction of other competent evidence on the question of impairment. So a result under 0.08 percent does not by itself end an (a) charge. The article on a DUI below the legal limit explains that situation.
Where Evidence Disputes Arise in 23152a Versus 23152b Cases
Because the counts differ, the disputes in each often differ too. In the (a) count, the focus tends to be on observations. Lighting, weather, footwear, medical conditions and the instructions given during field tests can all affect how those observations look on video or in a report. For a closer look at report problems, see DUI police report errors.
In the (b) count, the focus usually shifts to the test itself. CALCRIM No. 2111 includes an optional instruction letting jurors consider whether the testing followed the Title 17 regulations on alcohol testing. Breath instrument records and blood handling can become central. The guides to breathalyzer calibration records and a DUI blood retest cover those records.
Mouth alcohol and the time of the last drink can come up in both counts. The article on mouth alcohol DUI questions explains one such issue.
The DMV Looks at the 0.08 Level Separately
The DMV case does not wait for the court case. Under Vehicle Code section 13353.2, the department must immediately suspend the driving privilege of a person who drove with 0.08 percent or more. The section also covers drivers under 21, commercial drivers and drivers on DUI probation at lower levels.
Section 13353.2(e) calls the DMV determination a civil matter that is independent of guilt or innocence. It also says that if a court acquits the person of related criminal charges, the department must immediately reinstate the privilege. In addition, a renewed hearing right exists if charges under section 23152 are not filed or are dismissed for insufficient evidence, with the request due within one year of the arrest.
Because the administrative suspension rests on the alcohol level, the DMV side tracks the (b) count more closely than the (a) count. The DUI court versus DMV article and the DMV DUI hearing deadline guide cover the timing.
Other Charges That Can Appear Beside 23152a Versus 23152b
Section 23152 has more subdivisions than (a) and (b). Subdivision (d) sets a 0.04 percent limit for commercial motor vehicles, and subdivision (e) sets the same 0.04 percent limit when a passenger for hire is aboard. Subdivision (f) covers drugs, and subdivision (g) covers the combined influence of alcohol and drugs.
Drivers under 21 face a separate rule as well. Section 23140 makes it unlawful for a person under 21 to drive with 0.05 percent or more of alcohol in the blood. The guides on California CDL DUI cases, combined alcohol and drug DUI charges and California underage DUI rules explain those charges.
Why a High Reading Can Affect Sentencing
A higher number can carry weight beyond the (b) count. Vehicle Code section 23578 tells the court to consider a level of 0.15 percent or more, or a refusal of a breath or urine test, as a special factor. After a conviction under section 23152 or 23153, that factor may justify enhanced penalties or probation terms. The article on high BAC DUI consequences covers that topic.
An Invented Example of the Two Counts
This is an invented example that does not describe a real case. An officer stops a driver late at night for drifting within a lane. The officer notes the smell of alcohol and asks the driver to perform field sobriety tests. After the arrest, a breath test about 90 minutes later reads 0.09 percent.
The complaint lists a 23152(a) count based on the stop, the observations and the field tests. It also lists a 23152(b) count based on the breath result and the three hour presumption. The questions for each count differ. For the (a) count, a lawyer may review the video and the officer’s notes. For the (b) count, the lawyer may review the instrument records, the observation period and the drinking timeline. The example only shows how the counts separate and does not predict a result.
Questions to Ask About 23152a Versus 23152b Counts
A short list can help organize a first meeting with a lawyer. Which evidence supports each count, and which count looks weaker? Was the test taken within three hours of driving? Are there records from the breath instrument or the blood lab? What does the video show? How might the counts affect the DMV case and any plea discussion?
The article on DUI attorney consultation questions lists more topics to raise.
Frequently Asked Questions
Can Someone Be Charged With 23152(b) Without Seeming Drunk?
Yes. The (b) count does not require proof of impairment. CALCRIM No. 2111 lists only driving and a level of 0.08 percent or more at that time. Steady driving and good field test performance may still be relevant to the timing of the test and to the (a) count.
Does a Refused Test Mean Only the (a) Count Can Be Filed?
Not always. The (b) count needs evidence of the alcohol level, so without a test result the case often centers on the (a) count. A refusal also carries its own DMV consequences and can be a sentencing factor under section 23578. The article on California DUI test refusal covers those rules.
Is the 0.08 Standard the Same for Breath and Blood?
Yes, in legal terms. Section 23152 defines percent by weight as grams per 100 milliliters of blood or grams per 210 liters of breath. The method of testing can still raise its own evidence questions, which the PAS versus breath test article discusses.
Does an Out of State DUI Count as a Prior Under Section 23152?
It can. Vehicle Code section 23626 says a conviction in another state for an offense that would violate section 23152 or 23153 if committed in California counts as a conviction of that section for purposes of the Vehicle Code. Whether a specific out of state record qualifies depends on the offense and the record itself.
Is a Wet Reckless Plea an Option on These Counts?
Sometimes. A reduced charge is a negotiated outcome that depends on the evidence, the prosecutor and the court. The article on California wet reckless pleas explains how that charge works.
This article is general information about California DUI law, not legal advice. Laws change, and each situation depends on its own facts.