Idaho DUI Laws & Penalties
Last reviewed:
Overview
- Legal BAC limit: 0.08% (commercial 0.04%, under-21 0.02%, enhanced at 0.2%).
- Lookback period: 10 years. 10-year window for standard second-offense enhancement; 5-year window for the excessive-DUI felony escalation; third within 10 = felony.
- Primary statute: Idaho Code § 18-8004 (offense); § 18-8005 (penalties); § 18-8004C (excessive DUI)
0.20+ = 'excessive DUI' (§ 18-8004C): 10-day mandatory minimum jail (first 48 hrs consecutive) and 1-year absolute suspension even on a first offense; a second excessive DUI within 5 years is a FELONY.
Penalties by offense
| Offense | Classification | Jail | Fine | License suspension | Interlock |
|---|---|---|---|---|---|
| First offense | misdemeanor (excessive-DUI 0.20+ still misdemeanor but harsher) | none (standard) / 10 days (excessive 0.20+) – 6 months (standard) / 1 year (excessive); mandatory min none standard; 10 days if 0.20+ (48 hrs consecutive) | $0–$1,000 (up to $2,000 if excessive (0.20+)) | 90–180 days (30 absolute + restricted) – 1 year absolute (excessive); hardship: restricted permit after 30-day absolute period (standard) | Not required |
| Second offense | misdemeanor (within 10 years; felony if two excessive within 5) | 10 days (5 consecutive) – 1 year; mandatory min 10 days | $0–$2,000 | 1-year absolute suspension – 1 year; hardship: no restricted during absolute; IID after | Required |
| Third offense | felony (3rd within 10 years) | 30 days – 5 years (prison); mandatory min 30 days | $0–$5,000 | 1–5 year suspension – 5 years; hardship: IID path | Required |
First offense
- Classification: misdemeanor (excessive-DUI 0.20+ still misdemeanor but harsher)
- Jail: none (standard) / 10 days (excessive 0.20+) – 6 months (standard) / 1 year (excessive); mandatory min none standard; 10 days if 0.20+ (48 hrs consecutive)
- Fine: $0–$1,000 (up to $2,000 if excessive (0.20+))
- License suspension: 90–180 days (30 absolute + restricted) – 1 year absolute (excessive); hardship: restricted permit after 30-day absolute period (standard)
- Alternative disposition: Withheld judgment possible at court discretion for first offenders — avoids conviction on completion.
- Interlock: IID 1 year after suspension mandatory for excessive (0.20+) first offense.
Second offense
- Classification: misdemeanor (within 10 years; felony if two excessive within 5)
- Jail: 10 days (5 consecutive) – 1 year; mandatory min 10 days
- Fine: $0–$2,000
- License suspension: 1-year absolute suspension – 1 year; hardship: no restricted during absolute; IID after
- Interlock: IID 1 year post-suspension.
Third offense
- Classification: felony (3rd within 10 years)
- Jail: 30 days – 5 years (prison); mandatory min 30 days
- Fine: $0–$5,000
- License suspension: 1–5 year suspension – 5 years; hardship: IID path
- Also felony: any DUI with a prior felony DUI within 15 years.
Refusing a chemical test (implied consent)
Refusal (civil, § 18-8002): 1-year suspension first refusal + $250 civil penalty; 2 years second. Separate from the criminal DUI evidentiary-test refusal.
Statute: Idaho Code § 18-8002
Ignition interlock
IID mandatory 1 year after any excessive (0.20+) or repeat conviction; available for restricted driving on standard offenses.
Statute: Idaho Code § 18-8008
Frequently asked questions
What is the penalty for a first DUI in Idaho?
A first DUI in Idaho is a misdemeanor (excessive-DUI 0.20+ still misdemeanor but harsher). Jail: none (standard) / 10 days (excessive 0.20+) – 6 months (standard) / 1 year (excessive); mandatory min none standard; 10 days if 0.20+ (48 hrs consecutive). Fine: $0–$1,000 (up to $2,000 if excessive (0.20+)). License suspension: 90–180 days (30 absolute + restricted) – 1 year absolute (excessive); hardship: restricted permit after 30-day absolute period (standard).
What is the legal BAC limit in Idaho?
0.08% for most drivers, 0.04% for commercial drivers, and 0.02% for drivers under 21.
How long does Idaho look back at prior DUI offenses?
10 years. 10-year window for standard second-offense enhancement; 5-year window for the excessive-DUI felony escalation; third within 10 = felony.