A blood draw for a Montana DUI must be done by a physician, a registered nurse, or a qualified person working under their supervision, using a non-alcohol antiseptic and a tube with a preservative and an anticoagulant, and the sample must be analyzed by a laboratory the Department of Justice operates, certifies, or exempts. Those requirements come from two statutes and one administrative rule. This page walks through each of them. It is part of our Montana DUI Guide.
When Blood Is Used Instead of Breath
Under the implied consent law, the officer may designate which test or tests are administered (MCA § 61-8-1016(2)(b)). Breath is the usual choice for alcohol. Blood tends to be used when drugs are suspected, when the driver is at a hospital after a crash, when a breath sample cannot be given, or when a judge has issued a warrant after a refusal. Each of those has its own page: hospital blood tests after a crash and blood draw warrants.
Blood matters most in drug cases. Montana's limits for THC and the other listed drugs are written in nanograms per milliliter of blood (MCA § 61-8-1002(1)(d), (f)).
Who May Draw the Blood
MCA § 61-8-1019(1) limits who may withdraw blood at the request of a peace officer to "a licensed physician, registered nurse, or other qualified person acting under the supervision and direction of a physician or registered nurse." The statute adds that this limitation does not apply to the sampling of breath or oral fluid.
The phrase "supervision and direction" was tested in State v. Merry, 2008 MT 288, 345 Mont. 390, 191 P.3d 428. A licensed practical nurse drew the blood at a county health center while a registered nurse was on call but not in the building. The Court concluded that "a physician's or RN's physical presence is not required" and that a qualified person who draws blood subject to off-site or on-call supervision can satisfy the statute (¶ 19). The earlier section number in that opinion, § 61-8-405, is now § 61-8-1019.
A person who properly draws blood on an officer's written request has no civil or criminal liability for doing so (MCA § 61-8-1019(4)).
The Collection Rules in ARM 23.4.220
| Step | Requirement | Source |
|---|---|---|
| Who draws | A licensed physician, registered nurse, or other qualified person acting under their supervision and direction | MCA § 61-8-1019(1) |
| The request | Collected on the written request of a peace officer or officer of the court | ARM 23.4.220(1) |
| Skin preparation | An aqueous solution of a nonvolatile antiseptic. An alcohol solution may not be used | ARM 23.4.220(2) |
| The tube | Contains a preservative (sodium fluoride or equivalent) and an anticoagulant (potassium oxalate or equivalent) | ARM 23.4.220(6) |
| Labeling | Subject's name, date and time of collection, and an evidence seal signed and dated | ARM 23.4.220(3) |
| Witnessing | When possible, the requesting officer observes the collection | ARM 23.4.220(7) |
| Analysis | A laboratory operated or certified by the Department of Justice, or one exempt from certification | MCA § 61-8-1018(1)(b)(ii) |
The rule defines the two additives by their purpose. A preservative inhibits bacterial growth in the sample, and an anticoagulant prevents clotting (ARM 23.4.201(4), (21)). The Forensic Science Division supplies collection kits with approved tubes and request forms, and it reserves the right to accept or reject a sample submitted in a commercial kit (ARM 23.4.220(5)).
Volume matters too. A sample that does not meet the Division's required volume "will not be analyzed" (ARM 23.4.220(4)).
Where the Sample Is Analyzed
A blood test report is admissible if the sample "was analyzed in a laboratory operated or certified by the department or in a laboratory exempt from certification under the rules of the department" and the blood was drawn by a person competent to do so (MCA § 61-8-1018(1)(b)(ii)). In most cases that laboratory is the State's own, covered in the crime lab and toxicology reports.
The exempt category is mostly hospitals. Clinical and hospital laboratories under the direct supervision of a pathologist or certified medical technologist, and licensed or accredited as the rule describes, do not need Department certification (ARM 23.4.203). Blood drawn or analyzed by medical staff for treatment, and not at an officer's request, is exempt from the collection rules altogether (ARM 23.4.220(1)).
Timing: What the Law Does and Does Not Say
People often ask whether police have two hours, or three, to get a sample. The Montana DUI statutes we read do not set a number. What MCA § 61-8-1002(2) says is that the alcohol concentration at the time of a test, from a sample "drawn or taken within a reasonable time after the alleged act," gives rise to the statutory inferences about being under the influence.
The practical point is that a test measures the blood at the moment of the draw. The State then asks a judge or jury to connect that number to the earlier moment of driving. The longer the gap, the more that connection depends on evidence about when and what the person drank, and often on expert testimony.
Your Rights Around the Draw
- Information. On request, full information about any test given at an officer's direction must be made available to you or your attorney (MCA § 61-8-1019(3)).
- An independent test. You may request an independent blood sample drawn by a physician or registered nurse. The officer may not unreasonably impede that right, has no duty to transport you, and you pay for it (MCA § 61-8-1019(2)).
- The right to refuse. The officer must tell you of the right to refuse and that refusal will result in a license suspension of up to 1 year (MCA § 61-8-1016(2)(c)). What follows a refusal is covered on our test refusal page.
What a Defense Review Looks At
A blood case is reviewed link by link: the legal basis for the draw, the qualifications and supervision of the person who drew it, the antiseptic and tube, the seal and label, each transfer of custody, storage, and finally the laboratory's own records. The Department of Justice's manual for prosecutors acknowledges the same chain. It advises that it is generally best practice to call the person who drew the blood as a witness, while noting that some courts admit results without that testimony.
None of this means a blood result is unreliable. It means the result is evidence with a history, and the history can be checked. Our article on challenging the blood test explains how.
This page explains Montana law in general as of the 2025 Montana Code Annotated and the Administrative Rules of Montana in effect on October 9, 2026. It is not legal advice about your specific case.