Clearinghouse Queries: Full vs. Limited — Which One Do You Need and When?

The FMCSA Drug & Alcohol Clearinghouse requires two different types of queries, and using the wrong one at the wrong time is one of the most common compliance mistakes carriers make. A full query when you only needed a limited query wastes time and money. A limited query when you needed a full query is a federal violation. This guide explains exactly when to use each type, what they cost, what they show, and what to do when the results aren't clean.

What Is the FMCSA Clearinghouse?

The FMCSA Drug & Alcohol Clearinghouse is a federal database that tracks drug and alcohol violations for commercial motor vehicle (CMV) drivers. It went live on January 6, 2020, and became the sole method for reporting and querying violations on November 18, 2024. Every carrier that employs CDL drivers must use it.

The Clearinghouse contains records of positive drug tests, alcohol violations, refusals to test, and return-to-duty status for every CDL holder in the United States. Carriers are required to query the Clearinghouse at two specific points: before hiring a driver (pre-employment) and at least once per year for every active driver (annual query).

Full Query vs. Limited Query: Side-by-Side Comparison

When to Use a Full Query

A full query is required in two situations, and there are no exceptions.

1. Pre-Employment (Mandatory)

Before a driver performs any safety-sensitive function — which includes operating a CMV — the carrier must conduct a full Clearinghouse query. This is required under section 382.701(a). A limited query does not satisfy the pre-employment requirement.

The full query shows the complete details of any drug or alcohol violation on record, including:

• Type of violation (positive test, refusal, actual knowledge)
• Date of the violation
• Substance involved (for drug violations)
• Name of the reporting employer
• Whether the driver has completed the return-to-duty process
• SAP (Substance Abuse Professional) evaluation and treatment status
• Follow-up testing plan status

If the full query reveals an unresolved violation, you cannot hire the driver for any safety-sensitive position until they have completed the entire return-to-duty process and passed a return-to-duty test.

2. Follow-Up to a Positive Limited Query

If you run a limited query (for the annual requirement) and it comes back showing that records exist, you must follow up with a full query to see the details. The limited query only tells you yes or no — it does not reveal what the violation was or whether the driver has completed the return-to-duty process.

You cannot make an employment decision based on a positive limited query alone. The full query is necessary to determine:

• Whether the violation is resolved or unresolved
• Whether the driver completed the SAP process
• Whether the driver passed a return-to-duty test
• Whether follow-up testing is still in progress

How to Conduct a Full Query

1. Log in to the Clearinghouse at clearinghouse.fmcsa.dot.gov using your carrier account.
2. Select "Full Query" and enter the driver's information (CDL number, state of issuance, date of birth).
3. Request driver consent. The system sends a consent request to the driver's Clearinghouse account. The driver must log in to their own account and electronically approve the query.
4. Wait for consent. The driver has 24 hours to respond, though most approve within minutes if they're expecting the request. If the driver does not consent, the query cannot be completed.
5. Review the results. Once consent is granted, results are available immediately.
6. Document the outcome in the driver's qualification file — including the query date, confirmation number, and result.

When to Use a Limited Query

A limited query is designed for one specific purpose: the annual Clearinghouse check required under section 382.701(b). It tells you whether any records exist in the Clearinghouse for that driver — nothing more.

Annual Requirement (Mandatory)

Every carrier must query the Clearinghouse at least once every 12 months for each CDL driver they employ. A limited query satisfies this requirement. It is free and does not require the driver to log in and provide per-query electronic consent.

However, the driver must have signed a general consent form authorizing the carrier to conduct limited queries. This general consent can be obtained once — typically during onboarding — and covers all future limited queries for the duration of employment. Keep the signed consent form in the driver's qualification file.

How to Conduct a Limited Query

1. Verify general consent is on file. If the driver has not signed a general consent form, obtain one before running the query.
2. Log in to the Clearinghouse using your carrier account.
3. Select "Limited Query" and enter the driver's information.
4. Review the result. The response will be either "No records found" or "Records found."
5. If no records found: Document the query date and result in the driver's file. You're done until next year.
6. If records found: You must immediately conduct a full query to see the details. Do not allow the driver to continue operating a CMV until you've reviewed the full query results.

What to Do When You Find a Violation

Discovering a Clearinghouse violation — whether through a pre-employment full query or a follow-up to a positive limited query — triggers a specific sequence of required actions.

Unresolved Violation (Driver Has Not Completed Return-to-Duty)

• Remove the driver from safety-sensitive functions immediately. The driver cannot operate a CMV, load or unload hazardous materials, or perform any other safety-sensitive duty.
• Provide the driver with a list of SAPs (Substance Abuse Professionals) in their area. SAMHSA maintains a locator at findtreatment.gov.
• The driver must complete the SAP evaluation and follow all treatment recommendations.
• After treatment, the SAP conducts a follow-up evaluation to determine if the driver is ready for a return-to-duty test.
• The driver must pass a return-to-duty test (observed, directly supervised collection) before resuming safety-sensitive functions.
• Follow-up testing is required for a minimum of 12 months (up to 60 months) after return to duty, with at least 6 tests in the first 12 months.

Resolved Violation (Driver Completed Return-to-Duty)

If the full query shows a violation that has been resolved — meaning the driver completed the SAP process and passed the return-to-duty test — you can hire or retain the driver. However, you should:

• Verify the follow-up testing plan is documented and active
• Confirm whether follow-up testing is still required (check the dates)
• Document your review of the violation and your decision to hire or retain
• If the driver is still in the follow-up testing period, ensure your fleet's drug testing program accounts for the required follow-up tests

Common Mistakes Carriers Make with Clearinghouse Queries

Mistake 1: Using a Limited Query for Pre-Employment

This is the single most common Clearinghouse error. A limited query does not satisfy the pre-employment requirement under section 382.701(a). If an auditor finds that you hired a driver based on a limited query, it is a violation — even if the limited query showed no records. The regulation specifically requires a full query before the driver performs safety-sensitive functions.

Mistake 2: Not Following Up on a Positive Limited Query

Some carriers run the annual limited query, see "records found," and do nothing — either because they don't understand the result or because they're afraid of what the full query will show. Ignoring a positive limited query is a serious violation. You are required to follow up with a full query and take appropriate action based on the results.

Mistake 3: Not Obtaining General Consent for Limited Queries

Limited queries require a signed general consent form from the driver. Without it, the query is technically unauthorized. Collect the general consent form during onboarding and keep it in the driver's file. Unlike full query consent (which must be provided electronically per query), general consent is a one-time paper or electronic signature.

Mistake 4: Forgetting to Register in the Clearinghouse

Carriers must register in the Clearinghouse before they can run any queries. Registration is free but requires your USDOT number, company information, and designation of a Clearinghouse administrator. If you're a new carrier, complete registration during your authority setup — not when you need to hire your first driver.

Mistake 5: Allowing a Driver to Keep Driving After a Positive Result

This is the highest-risk mistake. If a full query reveals an unresolved violation and you allow the driver to continue operating a CMV, you're exposing your company to catastrophic liability. In the event of an accident, the Clearinghouse record will show that you knew about the violation and took no action. This can result in punitive damages, FMCSA enforcement action, and potential criminal liability.

Clearinghouse Query Costs and Budgeting

Understanding the cost structure helps you budget for Clearinghouse compliance:

• Carrier registration: Free
• Limited queries: Free (unlimited)
• Full queries: $1.25 each
• Driver registration: Free for drivers

For a fleet of 25 drivers, the annual Clearinghouse cost is minimal: 25 free limited queries for the annual requirement, plus $1.25 per new hire for pre-employment full queries. If you hire 10 drivers per year, your total Clearinghouse cost is approximately $12.50. Even for large fleets, the direct cost is negligible — the real expense is the administrative time to track due dates, run queries, and document results.

Record Keeping Requirements

Every Clearinghouse query — full or limited — must be documented in the driver's qualification file. The documentation should include:

• Date the query was conducted
• Type of query (full or limited)
• Result (no records found / records found / violation details for full queries)
• Clearinghouse confirmation number
• Name of the person who conducted the query
• Any follow-up actions taken (for positive results)

Retain these records for the duration of the driver's employment plus 3 years after termination. The Clearinghouse itself retains records for 5 years from the date of the violation (or until the violation is resolved, whichever is later), but your internal documentation must be maintained independently.

Frequently Asked Questions

Can I use a full query for the annual requirement instead of a limited query?

Yes. A full query satisfies both the pre-employment and annual requirements. Some carriers prefer to run full queries annually because they provide complete details without the two-step process of a limited query followed by a potential full query. The tradeoff is cost ($1.25 per query) and the need for per-query electronic consent from the driver. For most carriers, the limited query is sufficient for the annual check.

What if the driver refuses to consent to a full query?

If a prospective hire refuses to consent to the pre-employment full query, you cannot hire them for a safety-sensitive position. Period. If a current driver refuses consent for a follow-up full query (after a positive limited query), they must be immediately removed from safety-sensitive functions. A refusal to consent is treated the same as a refusal to test under DOT regulations.

How long does the driver have to respond to a full query consent request?

The Clearinghouse does not impose a strict deadline, but FMCSA guidance suggests the consent request expires after a reasonable period. In practice, most carriers tell drivers they need to respond within 24 hours. If the driver does not respond, you can resend the request. For pre-employment queries, the driver cannot start work until consent is granted and the query is complete.

Do owner-operators need to query themselves?

Yes. If you are an owner-operator who holds your own authority (you are both the carrier and the driver), you must query yourself in the Clearinghouse — a full query at the start of your authority and a limited query annually thereafter. You'll need to register as both a carrier and a driver in the Clearinghouse.

What if I find a violation for a driver I've employed for years?

The required response is the same regardless of tenure. If a query reveals an unresolved violation, the driver must be removed from safety-sensitive functions immediately. The driver's length of service, performance record, or personal circumstances do not create an exception to this requirement. Document the discovery, the action you took, and provide the driver with SAP referral information. The driver can return to duty only after completing the full return-to-duty process.