When is ICD-10 code R78 used?

Doctors, hospitals, and insurers may use ICD-10 code R78 when recording findings of drugs and other substances, not normally found in blood in a standardized format. This entry may also act as a broader category that points toward more specific child codes.

Does ICD-10 code R78 confirm a diagnosis?

No. A code helps standardize documentation and claims, but it should not be read as a substitute for a clinician's full assessment.

ICD10

ICD-10 Code R78: Findings of drugs and other substances, not normally found in blood

Name: ICD-10 Code R78: Findings of drugs and other substances, not normally found in blood
Creator: HealthAssure Clinical Team
Published: 2026-05-21T06:30:49.109Z

R78 is an ICD-10 diagnosis entry used to group records related to Findings of drugs and other substances, not normally found in blood. You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen. ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99).

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99).

When is it used?

May be used when a clinician documents findings of drugs and other substances, not normally found in blood in a patient's medical record.
May appear in hospital records, claims, referrals, and clinical documentation.
This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.

What it does not mean

A code alone does not explain severity, treatment plan, or outcome.
A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
This entry may represent a broader category rather than the most specific billable code.

Code hierarchy

chapter

18Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)

block

R70-R79Abnormal findings on examination of blood, without diagnosis

currentR70-R79

Official coding notes

Applicable to

code to identify the any retained foreign body, if applicable (Z18.-)

Excludes2 (may code together if documented)

mental or behavioral disorders due to psychoactive substance use (F10-F19)

Use additional code

code to identify the any retained foreign body, if applicable (Z18.-)

Where you may see this code

You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.

Related specialists

General PhysicianHematologist

Sibling codes

R70Elevated erythrocyte sedimentation rate and abnormality of plasma viscosity R71Abnormality of red blood cells R73Elevated blood glucose level R74Abnormal serum enzyme levels R75Inconclusive laboratory evidence of human immunodeficiency virus [HIV]billable R76Other abnormal immunological findings in serum R77Other abnormalities of plasma proteins R79Other abnormal findings of blood chemistry

Coding guidelines

Compatibility

Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.

Legacy codes

R78

Replacement codes

R78.0 — Finding of alcohol in bloodR78.1 — Finding of opiate drug in bloodR78.2 — Finding of cocaine in bloodR78.3 — Finding of hallucinogen in bloodR78.4 — Finding of other drugs of addictive potential in bloodR78.5 — Finding of other psychotropic drug in bloodR78.6 — Finding of steroid agent in bloodR78.9 — Finding of unspecified substance, not normally found in blood

Common synonyms

Findings of drugs and other substances, not normally found in blood

Frequently asked questions

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.