Violation code

383.23A2-S

Operating a CMV (School Bus) without a valid CDL: No school bus endorsement as described in 383.93(b)(5).

Driver Fitness8Non-OOS· SMS Appendix A v3.20

383.23A2-S is a License-related: High violation under 49 CFR §383.23A2-S. It falls in the Driver Fitness BASIC with a severity weight of 8/10. Nationally it was cited 19 times in the last five years, with an OOS rate of 94.7%.

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National roadside inspection stats

as of 6/20/2026

Inspections

that found this code

Violations

total written

OOS rate

94.7%

18 OOS

Source: FMCSA roadside inspection data (last 5 years). The OOS rate is the share of these violations that led the officer to mark the driver or vehicle out of service.

Violation group: License-related: High
Regulation §: 383.23A2-S
Severity weight: 8
Used in SMS: Yes
Status: Active
Updated: 6/20/2026

Last updated June 2026

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Notes

DSMS: Y | Comment: Added in 3.11 | Footnote: Violation added in Version 3.11 of the methodology and included with the September 25, 2020 snapshot.

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Challenging 383.23A2-S through FMCSA DataQs

If this violation was written incorrectly, here are the angles trucking-safety managers use to contest it. Playbook: Driver Fitness.

Common ways to challenge this code

Medical certificate was valid and on file
A valid medical examiner's certificate was in the driver's qualification file and was either not produced at roadside or not properly recognized.
Evidence that wins
- ✓Copy of the valid medical examiner's certificate
- ✓Driver qualification file index
- ✓National Registry verification printout
CDL class / endorsement was correct for the operation
The driver's CDL class and endorsements were correct for the vehicle and cargo being operated.
Evidence that wins
- ✓Copy of the valid CDL with endorsements
- ✓Vehicle registration showing GVWR/configuration
- ✓Bill of lading or shipping papers showing cargo

Common pitfalls — avoid these

⚠A medical certificate that expired the DAY of inspection still fails — there is no grace period

⚡ Draft a challenge for 383.23A2-S →Read the DataQs guide first

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Same BASIC category — ranked by national citation volume

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Codes under the same FMCSA violation group

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Frequently asked questions about 383.23A2-S

What does violation 383.23A2-S mean?

383.23A2-S is the FMCSA roadside-inspection violation code for "Operating a CMV (School Bus) without a valid CDL: No school bus endorsement as described in 383.93(b)(5).", part of the License-related: High group, cited under 49 CFR §383.23A2-S.

What BASIC does 383.23A2-S affect?

383.23A2-S falls under the Driver Fitness BASIC in the FMCSA Safety Measurement System (SMS).

What is the CSA severity weight of 383.23A2-S?

383.23A2-S carries a severity weight of 8 out of 10. Higher weights indicate violations more closely tied to crash risk, and they count more toward a carrier's Driver Fitness score.

Is 383.23A2-S an out-of-service (OOS) violation?

No. 383.23A2-S is not an out-of-service violation, so on its own it does not trigger an out-of-service order at the roadside.

How many CSA points does 383.23A2-S add to a carrier's score?

The point contribution of 383.23A2-S depends on its severity weight (8/10) multiplied by a time weight of 3, 2, or 1 based on how recent the inspection is. You can calculate the exact contribution with the CSA points calculator.

Can 383.23A2-S be challenged through DataQs?

Yes. If you believe 383.23A2-S was recorded in error, you can file a Request for Data Review (RDR) through the FMCSA DataQs system with supporting evidence. A successful challenge can remove or correct the violation on your record.

Keep going

CSA points calculator How to challenge a violation Draft a DataQs letter for 383.23A2-S Driver Fitness BASIC Carrier CSA lookup CSA glossary