2027 ICD-10-CM Diagnosis Code R78Findings of drugs and other substances, not normally found in blood

ICD-10-CM Codes›R00–R99›R70-R79›R78

ICD-10-CM R78
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

R78 is a non-billable ICD-10-CM category code for findings of drugs and other substances, not normally found in blood, so it cannot be submitted on claims. Use a more specific code from this category instead, such as R78.0, R78.1, R78.2, and R78.3. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established.

Code Identity

ICD-10-CM Code
R78
Billable Status
No — Non-Billable Category
Code Describes
Findings of drugs and other substances, not normally found in blood
Short Description
Find of drugs and oth substnc, not normally found in blood
Chapter
R70-R79
Abnormal findings on examination of blood, without diagnosis

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR70-R79Abnormal findings on examination of blood, without diagnosis
CategoryR78Findings of drugs and other substances, not normally found in blood
This CodeR78Findings of drugs and other substances, not normally found in blood

Specific Coding for Find of drugs and oth substnc, not normally found in bloodOverview

Non-specific codes like R78 require more characters. Use one of these billable codes instead:

  • Use R78.0 for Finding of alcohol in blood

  • Use R78.1 for Finding of opiate drug in blood

  • Use R78.2 for Finding of cocaine in blood

  • Use R78.3 for Finding of hallucinogen in blood

  • Use R78.4 for Finding of other drugs of addictive potential in blood

  • Use R78.5 for Finding of other psychotropic drug in blood

  • Use R78.6 for Finding of steroid agent in blood

  • R78.7 for Finding of abnormal level of heavy metals in blood

  • Use R78.71 for Abnormal lead level in blood

  • Use R78.72 for Abnormal gadolinium level in blood

  • Use R78.79 for Finding of abnormal level of heavy metals in blood

  • R78.8 for Finding of other specified substances, not normally found in blood

  • Use R78.81 for Bacteremia

  • Use R78.89 for Finding of other specified substances, not normally found in blood

  • Use R78.9 for Finding of unspecified substance, not normally found in blood

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to R78: its own notes plus those printed at block R70-R79 and Chapter 18. A note printed at a category, block or chapter applies to every code under it.

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

On R78 itself
  • mental or behavioral disorders due to psychoactive substance use (F10-F19)
From Block R70-R79 Abnormal findings on examination of blood, without diagnosis applies to 45 codes
  • abnormal findings on antenatal screening of mother (O28.-)
  • abnormalities of lipids (E78.-)
  • abnormalities of platelets and thrombocytes (D69.-)
  • abnormalities of white blood cells classified elsewhere (D70-D72)
  • coagulation hemorrhagic disorders (D65-D68)
  • diagnostic abnormal findings classified elsewhere - see Alphabetical Index
  • hemorrhagic and hematological disorders of newborn (P50-P61)
From Chapter 18 (R00-R99) Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified applies to 774 codes
  • abnormal findings on antenatal screening of mother (O28.-)
  • certain conditions originating in the perinatal period (P04-P96)
  • signs and symptoms classified in the body system chapters
  • signs and symptoms of breast (N63, N64.5)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

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

Notes

General instructions on how these codes are used.

From Chapter 18 (R00-R99) Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified applies to 774 codes
  • This chapter includes symptoms, signs, abnormal results of clinical or other investigative procedures, and ill-defined conditions regarding which no diagnosis classifiable elsewhere is recorded.
  • Signs and symptoms that point rather definitely to a given diagnosis have been assigned to a category in other chapters of the classification. In general, categories in this chapter include the less well-defined conditions and symptoms that, without the necessary study of the case to establish a final diagnosis, point perhaps equally to two or more diseases or to two or more systems of the body. Practically all categories in the chapter could be designated 'not otherwise specified', 'unknown etiology' or 'transient'. The Alphabetical Index should be consulted to determine which symptoms and signs are to be allocated here and which to other chapters. The residual subcategories, numbered .8, are generally provided for other relevant symptoms that cannot be allocated elsewhere in the classification.
  • The conditions and signs or symptoms included in categories R00-R94 consist of:
  • (a) cases for which no more specific diagnosis can be made even after all the facts bearing on the case have been investigated;
  • (b) signs or symptoms existing at the time of initial encounter that proved to be transient and whose causes could not be determined;
  • (c) provisional diagnosis in a patient who failed to return for further investigation or care;
  • (d) cases referred elsewhere for investigation or treatment before the diagnosis was made;
  • (e) cases in which a more precise diagnosis was not available for any other reason;
  • (f) certain symptoms, for which supplementary information is provided, that represent important problems in medical care in their own right.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name R78, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming R78: its condition is not part of those codes, and both may be reported when the patient has both.

  • Block R83-R89 Abnormal findings on examination of other body fluids, substances and tissues, without diagnosis
    abnormal findings on examination of blood, without diagnosis (R70-R79) names R70-R79, which includes this code

Use Additional Code 1

These codes say to use an additional code from the note, and R78 is one of the codes named.

  • Z02.83 Encounter for blood-alcohol and blood-drug test
    code for findings of alcohol or drugs in blood (R78.-)

Patient EducationClinical

Laboratory Tests

Laboratory tests check a sample of your blood, urine, or body tissues. A technician or your doctor analyzes the test samples to see if your results fall within the normal range. The tests use a range because what is normal differs from person to person. Many factors affect test results. These include:

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About R78Overview

What is the ICD-10 code for findings of drugs and other substances, not normally found in blood?

R78 is the ICD-10-CM category for findings of drugs and other substances, not normally found in blood, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is R78 a billable code?

No. This is a category header that groups the codes for findings of drugs and other substances, not normally found in blood, and headers cannot be submitted on claims. Claims for findings of drugs and other substances, not normally found in blood need a more specific code from this category, such as R78.0, R78.1, and R78.2.

Can R78 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the findings of drugs and other substances, not normally found in blood is established, that condition takes the principal position instead.

Does R78 need an additional code?

When the condition applies, yes. The Use Additional Code note reads: code to identify any retained foreign body, if applicable (Z18.-). The additional code is reported after R78.