By Stephen E. Mays, Mays Law Office · October 2026
Can police do a saliva test for drugs in Wisconsin? Yes. Since March 15, 2026, Wis. Stat. § 343.303 (2025 Wisconsin Act 99) lets an officer request breath, oral fluid, or both before an arrest, on a DOT-approved device. The result can support probable cause to arrest, not prove impairment, and the sample must be destroyed or returned. Mays Law Office (Middleton) defends drug-OWI charges.
For decades, Wisconsin’s roadside screening test meant one thing: a breath sample given before any arrest. In 2026 the Legislature changed that. A driver an officer has probable cause to believe is operating while intoxicated can now be asked for a saliva sample instead of, or along with, a breath sample, and the same rule reaches boats, snowmobiles, ATVs and off-highway motorcycles. A second 2026 law rewrote the warning officers read before the evidentiary blood, breath or urine test, and a third, which changes ignition interlock rules, is on the books but not yet in effect.
This article explains what the new roadside test is, what its result can and cannot be used for, what happens next, and how a drug-OWI charge is actually proven. Every statute quoted below was verified against the Wisconsin Statutes as the Legislature publishes them, updated through October 1, 2026.
What Act 99 Changed in § 343.303: Breath, Oral Fluid or Both, Before an Arrest
2025 Wisconsin Act 99 (2025 Senate Bill 678) was enacted March 13, 2026 and published March 14, 2026. It does not set its own effective date, so under Wis. Stat. § 991.11 it took effect “on the day after its date of publication”: March 15, 2026. The Legislative Council’s memo on the act states the same effective date.
The heart of the change is one phrase in Wis. Stat. § 343.303, now titled “Preliminary screening test.” The officer, “prior to an arrest, may request the person to provide a sample of his or her breath or oral fluids, or both, for a preliminary screening test using a device approved by the department for this purpose.”
Three details in that sentence matter:
- There is a threshold. The request is allowed when the officer “has probable cause to believe that the person is violating or has violated” the OWI statute, § 346.63(1) or (2m), or certain related offenses. Commercial drivers are covered by a separate trigger: the officer may also ask if the officer “detects any presence of alcohol, a controlled substance, controlled substance analog or other drug, or a combination thereof” on a person driving or on duty with a commercial motor vehicle.
- It happens before an arrest. This is a screening step that helps the officer decide what to do next. It is not the formal chemical test.
- It requires an approved device. “Department” here means the Wisconsin Department of Transportation (§ 340.01(12)). The statute authorizes oral-fluid screening only with a device that department approves. Wisconsin’s administrative rule on approved testing instruments, Wis. Admin. Code ch. Trans 311, addresses breath-alcohol instruments and says nothing about oral fluids, so whether an approved saliva device was actually used at your stop is a fact to confirm in your own case.
The same rule on the water, the trails and the snow
Act 99 made matching changes for all-terrain and utility terrain vehicles (§ 23.33(4g)), off-highway motorcycles (§ 23.335(12)(e)), boats (§ 30.682) and snowmobiles (§ 350.102). Each of those sections says a person “shall provide a sample of his or her breath or oral fluids, or both, for a preliminary screening test” when an officer with probable cause asks before an arrest, and each then adds, in nearly the same words, that “[t]here is no penalty for a violation” of that requirement. Each also carries its own version of the destroy-or-return rule described below.
Can Police Do a Saliva Test for Drugs in Wisconsin? What the Result Can and Cannot Do
The screening result has two permitted uses. Under § 343.303, the officer may use it “for the purpose of deciding whether or not the person shall be arrested” for an OWI-related offense “and whether or not to require or request chemical tests as authorized under s. 343.305 (3).”
Its use in court is narrow:
“The result of the preliminary screening test shall not be admissible in any action or proceeding except to show probable cause for an arrest, if the arrest is challenged, or to prove that a chemical test was properly required or requested of a person under s. 343.305 (3).”
In plain terms, a roadside saliva result can help justify the arrest and the request for a formal test. It is not evidence that you were impaired, and it is not the test result the State uses to try the case.
The destroy-or-return rule
Act 99 also limits what happens to the saliva sample itself. “A law enforcement officer may collect and retain a sample of a person’s oral fluids only to the extent necessary to perform a preliminary screening test under this section and shall destroy the sample, or return the sample to the person, after conducting the preliminary screening test.” And: “A law enforcement officer may not collect or retain a sample of a person’s oral fluids under this section for any purpose other than a preliminary screening test.” If a saliva sample from your stop was kept, sent to a lab or used for anything else, that is worth raising with your lawyer.
Declining the roadside screen versus refusing the evidentiary test
These are two different requests with two different sets of rules. For the roadside screen, § 343.303 says: “The general penalty provision under s. 939.61 (1) does not apply to a refusal to take a preliminary screening test.” The boating, snowmobile, ATV and off-highway motorcycle sections say there is “no penalty” for not providing the screening sample.
The evidentiary test that may follow an arrest is a different matter, with license consequences explained in the next section. Whether to provide any sample is a decision that depends on the facts of the moment, and this article does not tell you to do or refuse either one.
After the Screen: The Evidentiary Test, the Act 195 Warning, and What Refusing Costs
If the officer arrests you for OWI, the next step is the evidentiary test under Wis. Stat. § 343.305. “Upon arrest,” the officer “may request the person to provide one or more samples of his or her breath, blood or urine” (§ 343.305(3)(a)). Section 343.303 itself makes the sequence explicit: “Following the screening test, additional tests may be required or requested of the driver under s. 343.305 (3).” For a suspected drug OWI, the evidentiary sample is the one that matters at trial, and a blood sample may be drawn only by a physician, registered nurse, medical technologist, physician assistant, phlebotomist or other authorized medical professional, or a person acting under a physician’s direction (§ 343.305(5)(b)).
2025 Wisconsin Act 195 rewrote the warning
2025 Wisconsin Act 195 (2025 Assembly Bill 856) was enacted April 3, 2026 and published April 4, 2026, and the Legislative Council’s memo gives its effective date as April 5, 2026. Its title describes it as “relating to: repealing unconstitutional provisions related to operating while intoxicated.” It repealed § 343.305(3)(ar) and (3)(b) and rewrote the statement in § 343.305(4) that an officer must read when requesting the evidentiary test. The current text reads:
“You have either been arrested for an offense that involves driving or operating a motor vehicle after using alcohol or drugs, or both, or you are suspected of driving or being on duty time with respect to a commercial motor vehicle after using alcohol or drugs, or both.
This law enforcement agency now wants to test one or more samples of your breath, blood or urine to determine the concentration of alcohol or drugs in your system. If any test shows more alcohol in your system than the law permits while driving or a detectable amount of a restricted controlled substance, your operating privilege will be suspended. If you refuse any requested test, your operating privilege will be revoked and you will be subject to other penalties. The test results or the fact that you refused testing can be used against you in court.
If you take all the requested tests, you may also choose to take the alternative test that this law enforcement agency provides free of charge. You may also have a test conducted by a qualified person of your choice at your expense. You, however, will have to make your own arrangements for that test.
If you have a commercial driver license or were operating a commercial motor vehicle, other consequences may result from positive test results or from refusing testing, such as being placed out of service or disqualified.”
Two other changes are worth knowing. The former subsection (3)(b), which addressed drivers who are unconscious or otherwise unable to withdraw consent, is gone, so a blood draw from a driver who cannot respond now needs some other lawful basis, such as a warrant; the statute itself says it “does not limit the right of a law enforcement officer to obtain evidence by any other lawful means” (§ 343.305(3)(c)). And the act’s marked-up text shows what changed in the warning itself: “while under the influence of” became “after using,” the former clause about a driver involved in an accident causing death or great or substantial bodily harm was struck, “a detectable amount of a restricted controlled substance” was added as a ground for suspension, and “[i]f you refuse any requested test” replaced the older refusal wording.
What refusing the evidentiary test costs
Refusing a test requested under § 343.305(3)(a) starts a separate refusal case. The officer prepares a notice of intent to revoke, and the notice tells the driver “[t]hat the person may request a hearing on the revocation within 10 days” (§ 343.305(9)(a)4.). If the court finds an improper refusal, or if no hearing is requested in time, the court revokes the operating privilege for one year for a first improper refusal, with longer revocations of two and three years as prior offenses are counted, and those periods “are doubled” if a passenger under 16 was in the vehicle (§ 343.305(10)(b)). An improper refusal also requires the court to order an ignition interlock restriction, a 24/7 sobriety program, or both (§ 343.301(1g)). And a refusal finding does not end the OWI case: the statute “does not preclude the prosecution of the person for violation of s. 346.63” (§ 343.305(9)(d)). Our post on what happens if you refuse a breathalyzer test in Wisconsin covers the refusal hearing in more detail.
Why a Saliva “Positive” Is Not a Conviction
A roadside screen can lead to an arrest, but a drug-OWI charge is proven, if at all, with admissible evidence under § 346.63. There are two main routes, often charged together.
The restricted-controlled-substance charge, § 346.63(1)(am)
This charge applies when “[t]he person has a detectable amount of a restricted controlled substance in his or her blood.” The word is blood, not saliva. “Restricted controlled substance” is defined in § 340.01(50m), and the list is narrower than many people assume:
- a schedule I controlled substance “other than a tetrahydrocannabinol”;
- “[t]he heroin metabolite 6-monoacetylmorphine”;
- a controlled substance analog of a schedule I substance;
- “[c]ocaine or any of its metabolites”;
- “[m]ethamphetamine”; and
- “[d]elta-9-tetrahydrocannabinol, excluding its precursors or metabolites, at a concentration of one or more nanograms per milliliter of a person’s blood.”
That last line matters for cannabis cases: the statute counts delta-9-THC itself, measured in blood at one nanogram per milliliter or more, and excludes its metabolites. The statute also creates a defense for a defendant who proves “by a preponderance of the evidence” a valid prescription for methamphetamine or one of its metabolic precursors, gamma-hydroxybutyric acid, or delta-9-tetrahydrocannabinol at the time of the incident (§ 346.63(1)(d)).
The impairment charge, § 346.63(1)(a)
The other route requires proof that the driver was “under the influence of an intoxicant, a controlled substance, a controlled substance analog” or a combination, or “under the influence of any other drug to a degree which renders him or her incapable of safely driving.” That “any other drug” language is not limited to the restricted list, so it can reach medications, but only on proof that the drug made the driver incapable of safely driving. Our post on OWI versus PAC charges in Wisconsin explains how an impairment count and a numeric count work side by side.
The two theories can be charged together, but if the State proves more than one for the same incident, “there shall be a single conviction for purposes of sentencing” (§ 346.63(1)(c)).
The questions that usually decide a drug-OWI case
Because the roadside result cannot prove impairment, the case turns on the steps around it. In a drug-OWI defense, we examine whether the stop itself was lawful; whether the officer had probable cause to believe an OWI violation was occurring before requesting the screen; whether any oral-fluid device used was one the Department of Transportation approved; whether the § 343.305(4) warning was read as the statute now requires; who drew the blood and how the sample was handled and tested; and, on an impairment charge, what the officer actually observed. None of those questions has a guaranteed answer, but each is a place to test the State’s case.
Penalties: the same ladder as any OWI
A drug-OWI follows the same penalty structure as an alcohol OWI, tied to the offense number. A first offense, without aggravating factors such as a passenger under 16, is a civil forfeiture: the driver “[s]hall forfeit not less than $150 nor more than $300” (§ 346.65(2)(am)1.), with license and other consequences on top. Later offenses carry escalating fines and jail, and a fourth offense is a Class H felony (§ 346.65(2)(am)4.). See our guide to a first-offense OWI in Wisconsin for the full picture.
Act 210’s interlock changes are not law until September 1, 2027
You may also read about 2025 Wisconsin Act 210 (2025 Senate Bill 248), enacted April 8, 2026 and published April 9, 2026, which overhauls ignition interlock and occupational-license rules. It is not in effect yet. Its Section 18 provides that it “takes effect on the first day of the 12th month beginning after the date specified in the notice published in the Wisconsin administrative register,” and the Wisconsin Statutes now print its changes with the note “eff. 9-1-27 by 2025 Wis. Act 210.” Until then, today’s interlock rules apply; see our guide to ignition interlock requirements in Wisconsin.
If You Were Asked for a Saliva Sample: What to Write Down Now
Details fade quickly after a stop, and in these cases the details are the defense. As soon as you can, write down:
- the time and place of the stop, and the reason the officer gave for it;
- what the officer said before asking for a saliva or breath sample, and whether you provided one;
- what you saw happen to the saliva sample afterward, if you provided one;
- whether you were arrested, and what test was requested afterward (breath, blood or urine), where, and by whom;
- whether the officer read you a warning before the evidentiary test, and whether you received a notice of intent to revoke; and
- every medication you had taken, with doses and times.
If you received a notice of intent to revoke after a refusal, mark the date. The statute gives you 10 days to request a hearing, and that clock does not wait.
Charged With a Drug OWI in Wisconsin? Talk With Mays Law Office
Roadside saliva screening is new in Wisconsin, and new procedures are where mistakes happen: a device that was not approved, a sample that was not destroyed or returned, a warning read from an outdated form, or a blood result that does not show what the State says it shows. We examine whether the stop and every test that followed were lawful, and we pursue the defenses the facts support.
Stephen E. Mays worked in the Dane County District Attorney’s office before becoming a defense attorney, and he now defends OWI and criminal cases throughout Wisconsin from our Middleton office. To schedule a free, confidential consultation, contact us online and tell us how we can reach you, or learn more about our OWI defense practice. We cannot promise a result, but we can make sure the State is held to what the Wisconsin Statutes actually require.
This article provides general legal information and is not legal advice. Reading it does not create an attorney-client relationship. Laws change and every case turns on its specific facts. Consult a licensed Wisconsin attorney about your situation.
Verified against the Wisconsin Statutes (updated through October 1, 2026): § 343.303; § 343.305; § 343.301; § 346.63; § 346.65; § 340.01; § 991.11; §§ 23.33(4g), 23.335(12)(e), 30.682 and 350.102; 2025 Wisconsin Act 99; 2025 Wisconsin Act 195; 2025 Wisconsin Act 210; Wis. Admin. Code ch. Trans 311.