(a) In this article, “ignition interlock device” means a device that uses a deep-lung breath analysis mechanism to make impractical the operation of the motor vehicle if ethyl alcohol is detected in the breath of the operator.
(b) The court may require as a condition of community supervision that a defendant placed on community supervision after conviction of an offense under Sections 49.04-49.08, Penal Code, have an ignition interlock device installed on the motor vehicle owned by the defendant or on the vehicle most regularly driven by the defendant and that the defendant not operate any motor vehicle that is not equipped with that device.

(c) The court shall require as a condition of community supervision that a defendant described by Subsection (b) have an ignition interlock device installed on the motor vehicle owned by the defendant or on the vehicle most regularly driven by the defendant and that the defendant not operate any motor vehicle unless the vehicle is equipped with that device if:
(1) it is shown on the trial of the offense that an analysis of a specimen of the defendant’s blood, breath, or urine showed an alcohol concentration level of 0.15 or more at the time the analysis was performed;
(2) the defendant is placed on community supervision after conviction of an offense under Sections 49.04-49.061, Penal Code, for which the defendant is punished under § 49.09(a) or (b), Penal Code; or
(3) the court determines under Subsection (d) that the defendant has one or more previous convictions under Sections 49.04-49.08, Penal Code.
(d) Before placing on community supervision a defendant convicted of an offense under Sections 49.04-49.08, Penal Code, the court shall determine from criminal history record information maintained by the Department of Public Safety whether the defendant has one or more previous convictions under any of those sections. A previous conviction may not be used for purposes of restricting a defendant to the operation of a motor vehicle equipped with an ignition interlock device under Subsection (c) if:
(1) the previous conviction was a final conviction under § 49.04, 49.045, 49.05, 49.06, 49.061, 49.07, or 49.08, Penal Code, and was for an offense committed before the beginning of the 10-year period preceding the date of the instant offense for which the defendant was convicted and placed on community supervision; and
(2) the defendant has not been convicted of an offense under § 49.04, 49.045, 49.05, 49.06, 49.061, 49.07, or 49.08, Penal Code, committed within the 10-year period preceding the date of the instant offense for which the defendant was convicted and placed on community supervision.
(e) Notwithstanding any other provision of this subchapter or other law, a judge who places on community supervision a defendant who was younger than 21 years of age at the time of the offense and was convicted for an offense under Sections 49.04-49.08, Penal Code, shall require as a condition of community supervision that the defendant not operate any motor vehicle unless the vehicle is equipped with an ignition interlock device.
(e-1) Except as provided by Subsection (e-2), a judge granting deferred adjudication community supervision to a defendant for an offense under § 49.04 or 49.06, Penal Code, shall require that the defendant as a condition of community supervision have an ignition interlock device installed on the motor vehicle owned by the defendant or on the vehicle most regularly driven by the defendant and that the defendant not operate any motor vehicle that is not equipped with that device. If the judge determines that the defendant is unable to pay for the ignition interlock device, the judge may impose a reasonable payment schedule, as provided by Subsection (f). If the defendant provides the court evidence under § 709.001, Transportation Code, sufficient to establish that the defendant is indigent for purposes of that section, the judge may enter in the record a finding that the defendant is indigent and reduce the costs to the defendant by ordering a waiver of the installation charge for the ignition interlock device and a 50 percent reduction of the monthly device monitoring fee. A reduction in costs ordered under this subsection does not apply to any fees that may be assessed against the defendant if the ignition interlock device detects ethyl alcohol on the breath of the person attempting to operate the motor vehicle.
(e-2) A judge may waive the ignition interlock requirement under Subsection (e-1) for a defendant if, based on a controlled substance and alcohol evaluation of the defendant, the judge determines and enters in the record that restricting the defendant to the use of an ignition interlock is not necessary for the safety of the community.
(f) The court shall require the defendant to obtain an ignition interlock device at the defendant’s own cost before the 30th day after the date of conviction unless the court finds that to do so would not be in the best interest of justice and enters its findings on record. The court shall require the defendant to provide evidence to the court within the 30-day period that the device has been installed on the appropriate vehicle and order the device to remain installed on that vehicle for a period the length of which is not less than 50 percent of the supervision period. If the court determines the defendant is unable to pay for the ignition interlock device, the court may impose a reasonable payment schedule not to exceed twice the length of the period of the court’s order.
(g) The Department of Public Safety shall approve ignition interlock devices for use under this article. § 521.247, Transportation Code, applies to the approval of a device under this article and the consequences of that approval.
(h) Notwithstanding any other provision of this subchapter, if a defendant is required to operate a motor vehicle in the course and scope of the defendant’s employment and if the vehicle is owned by the employer, the defendant may operate that vehicle without installation of an approved ignition interlock device if the employer has been notified of that driving privilege restriction and if proof of that notification is with the vehicle. The employment exemption does not apply if the business entity that owns the vehicle is owned or controlled by the defendant.