ICD code Y90.2 – Blood alcohol level 40-59 mg/100mL

Key takeaways

ICD-10 code Y90.2 documents a measured blood alcohol level of 40-59 mg/100 mL (0.040-0.059 g/dL) and is always a secondary code.

A quantitative laboratory BAC result between 40 and 59 mg/100 mL must appear in the medical record before you assign this code.

A result of 60 mg/100 mL moves the code up to Y90.3, and a result of 39 moves it down to Y90.1.

Y90.2 records a measured ethanol level rather than an alcohol use disorder, so it never replaces an F10 code.

Pabau, our practice management and billing platform, checks ICD-10 codes before claims go out, so Y90.2 sequencing errors surface early.

ICD-10 code Y90.2: Quick-reference code summary

ICD-10 code Y90.2 records a laboratory-measured blood alcohol level of 40-59 mg/100 mL and is always reported as a secondary code. It belongs to Chapter 20 of ICD-10-CM (External Causes of Morbidity), Category Y90 (Evidence of alcohol involvement determined by blood alcohol level). The table below captures the core reference data at a glance.

What ICD-10 code Y90.2 covers

ICD-10 code Y90.2 records one clinical fact: a laboratory-confirmed blood alcohol concentration (BAC) between 40 and 59 mg per 100 mL. Because the code captures a measurement, any condition, behavior or disorder behind it needs a code of its own.

The Y90.2 range sits below the most widely used legal driving threshold. In 49 states the per se driving limit is 0.08 g/dL; Utah’s is 0.05. A Y90.2 result of 0.040-0.059 g/dL is below the 0.08 limit, while a result of 50-59 mg/100 mL meets Utah’s limit. An ICD-10-CM code records the clinical measurement only. Whether a driver was over the limit is a legal question that stays off the claim.

Y90.2 typically appears on emergency department visits after trauma with a documented toxicology screen, and on inpatient admissions where alcohol involvement is recorded. It applies to any encounter where a measured BAC of 40-59 mg/100 mL appears in the record alongside a primary diagnosis.

Includes and Excludes notes for Y90.2

The ICD-10-CM Tabular List places Y90.2 within the Y90 category (Evidence of alcohol involvement determined by blood alcohol level). There are no Excludes1 or Excludes2 notes specific to Y90.2 itself. The Y90 category does carry a “code first” note for any associated alcohol-related disorder (F10). The broader Chapter 20 guidelines also apply, so these codes supplement the primary diagnosis and never replace it.

• What Y90.2 includes: any encounter where a laboratory BAC result of 40-59 mg/100 mL is documented in the record
• What Y90.2 does not include: alcohol use disorder diagnoses, which belong in F10.x. It also excludes suspected intoxication without a quantitative lab result, and encounters that document clinical signs of intoxication but no measured BAC.
• Cannot be PDX: per ICD-10-CM Official Coding Guidelines, Chapter 20, external cause codes are never sequenced as the principal diagnosis on any claim type

The Y90 code series: Where Y90.2 fits

Y90.2 is one of ten codes in the Y90 series, each covering a distinct BAC range. Picking a neighboring code by mistake is the main accuracy risk in this category. The table below shows the full series alongside the clinical context for each range.

The ten codes run in consecutive bands, so every measured result maps to exactly one code. A result of exactly 40 mg/100 mL is Y90.2, and so is a result of 59. At 60 the code becomes Y90.3, and at 39 it drops to Y90.1. When the record confirms alcohol but gives no measured level, the code is Y90.9 instead.

The chart below sets each band against the two per se driving limits, so you can see how narrow the Y90.2 window is.

Y90.2 vs Y90.3: Choosing the correct blood alcohol code

Y90.2 covers 40-59 mg/100 mL, and Y90.3 covers 60-79 mg/100 mL. The boundary is the number in the lab report. Assign Y90.2 when the result is 40 to 59, and Y90.3 when it is 60 to 79. There is no rounding or clinical judgment involved. The code follows the documented number exactly.

The most common assignment error occurs when a coder works from a handwritten note that says “BAC elevated, approximately 0.06” instead of the laboratory printout. A note stating “approximately 0.06 g/dL” could represent anywhere from 55 to 65 mg/100 mL. If the measured BAC is 60 or higher, Y90.3 applies, not Y90.2. Coders should always trace back to the quantitative lab result, not the provider’s narrative summary.

Y90.2 vs F10 alcohol use disorder codes: Key differences

Y90.2 and the F10.x codes are not interchangeable. They document different clinical facts and come from different chapters of ICD-10-CM.

Take a patient who presents to the ED after a fall, with a BAC of 52 mg/100 mL and a documented alcohol use disorder. The claim carries the primary injury code, an F10.x code for the disorder, and Y90.2 for the measured BAC. The F10 reference covers how to pick the disorder code that sits ahead of Y90.2.

How to use Y90.2 as a secondary code

Y90.2 is always a secondary code. Per ICD-10-CM Official Coding Guidelines, Chapter 20, external cause codes supplement the principal diagnosis and are never sequenced first. The coding sequence for an encounter involving Y90.2 follows these steps.

1. Assign the primary diagnosis first. This is the condition that drove the encounter: an injury (fracture, laceration, contusion), poisoning, or other condition for which treatment was provided.
2. Add any documented alcohol-related disorder code. The Y90 category says to code first any associated F10 disorder, so it goes ahead of Y90.2.
3. Add Y90.2 for the measured BAC. Confirm the lab result reads 40 to 59 mg/100 mL. Y90.2 answers “was alcohol involved?” with a quantified answer.
4. Add place-of-occurrence and activity codes as applicable. For inpatient claims, most facilities assign external cause codes routinely. Outpatient guidelines allow but do not universally require them.
5. Verify the primary code is not from Chapter 20. If the only diagnosis assigned is Y90.2, the claim will reject. It requires a companion primary code.

Pabau, the practice management and billing platform we build, checks codes against its built-in ICD-10 catalog before a claim goes to the Claim.MD clearinghouse. A Y90.2 sitting in the primary position gets flagged before submission.

Documentation requirements for Y90.2

Three documentation elements must be present in the medical record before a coder can assign Y90.2. Missing any one of them leaves the code unsupported and creates audit risk.

• Quantitative BAC laboratory result: the report must show a value of 40-59 mg/100 mL, or an equivalent in a unit that converts. A clinical note stating “patient appeared intoxicated” is not sufficient. A breath test result alone, without a blood laboratory confirmation, may not meet documentation standards depending on payer policy.
• Ordering provider attestation: the record should link the BAC result to the encounter. This is typically satisfied when the lab was ordered by the treating provider and the result is filed within the encounter documentation.
• Timing of specimen: the BAC must relate to the current encounter. A BAC from a prior visit cannot support Y90.2 on a new encounter date. The exception is a prior result explicitly referenced as clinically relevant to the current episode.

Pabau’s claims management software links encounter documentation to claim data. The BAC result and its external cause code travel through the workflow together, so nobody codes them later from incomplete notes.

The same evidence trail supports every other code on the claim. Our guide to clean claims covers the supporting documentation payers expect.

Payer requirements and pre-authorization considerations

External cause codes, including Y90.2, are generally optional rather than required on outpatient claims under current CMS guidance. Several situations still make them worth reporting.

• Inpatient claims (UB-04): most facility billers include external cause codes as standard practice on inpatient claims. The Uniform Hospital Discharge Data Set (UHDDS) guidance supports their use for data completeness.
• State Medicaid programs: some state Medicaid programs require external cause codes on specific claim types, particularly for injury-related encounters. Requirements vary by state; verify with the relevant state Medicaid agency.
• Commercial payers: payer policies differ. Some commercial contracts require external cause codes on trauma claims; others treat them as informational. Check the payer’s policy or contract terms.
• NCCI edits: the National Correct Coding Initiative (NCCI) does not typically generate bundling edits based on external cause codes alone. Still, check the NCCI edit tables against the specific procedure codes billed on the same claim. Verify current NCCI table versions before assuming no edit applies.

The CMS ICD-10 codes resource page provides current coding guidelines and annual update files. For Medicare claims, Chapter 25 of the CMS Medicare Claims Processing Manual covers the external cause code fields on the UB-04 institutional claim.

Common claim denial reasons for Y90.2

Denials on Y90.2 claims follow recognizable patterns. Most are preventable with pre-submission validation. The table below pairs each denial reason with its fix.

How to correct and resubmit a denied Y90.2 claim

When a Y90.2 claim is denied, the resubmission process follows a standard external cause code appeal workflow.

1. Identify the denial reason code (CARC). Pull the Explanation of Benefits or 835 remittance advice. The CARC code will indicate whether the denial was for sequencing, documentation, or a payer-specific policy restriction.
2. Audit the original claim against the medical record. Confirm the quantitative BAC lab result is in the file and falls within 40-59 mg/100 mL. Then check that Y90.2 sits in an additional code position, not PDX.
3. Correct the claim. Fix the identified error: resequence codes, add missing documentation, or swap the Y90 code if the wrong range was selected.
4. Resubmit within timely filing limits. Medicare’s standard timely filing limit for resubmissions is one year from the date of service. Commercial payer limits vary; check the applicable contract.

For a reference on denial reason codes, see the denial codes in medical billing guide.

How Pabau supports accurate Y90.2 claims

Many billing teams code Y90.2 after the encounter, working from a narrative note and a lab printout filed somewhere else. That is where range errors and sequencing errors creep in.

Pabau keeps the encounter documentation, the ICD-10 catalog, and the claim in one workflow. Codes are validated before the claim reaches the Claim.MD clearinghouse, so a Y90.2 in the primary position is caught early.

When a denial does come back, the clearinghouse integration supports denial management workflows. Electronic remittance retrieval and corrected claim resubmission run in one place, so billing teams can act on Y90.2 denials without tracking each step by hand.

Reduce external cause code denials before they happen

Pabau checks ICD-10 code sequencing before claims go out, so coders catch a misplaced Y90.2 before the payer does.

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Conclusion

Y90.2 is a narrow code with a hard ceiling at 59 mg/100 mL. Code it only from a quantitative lab result for the current encounter, and always behind a primary diagnosis. When a note gives the BAC in g/dL, convert it before you choose between Y90.1, Y90.2, and Y90.3.

Pulling the lab report adds a minute per chart. That minute prevents the range errors that turn into corrected claims and audit findings later.

Practices that link their clinical documentation directly to their billing workflow catch these errors at the source. Pabau’s medical billing workflow integrates ICD-10 code validation through the Claim.MD clearinghouse, from encounter documentation through to paid claim. Book a demo to see how Pabau keeps external cause codes like Y90.2 accurate for your billing team.

Continue your research

Need to understand how electronic claims reach payers? Medical claims clearinghouse overview explains how 837P transactions are processed and validated before reaching Medicare and commercial payers.

Coding alcohol dependence alongside the BAC? ICD-10 code F10.20 explains the uncomplicated alcohol dependence code that is sequenced ahead of Y90.2.

Looking for electronic remittance guidance after a denial? Electronic remittance advice (ERA) guide walks through reading 835 files and identifying CARC denial codes for corrected claim resubmission.

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