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

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Coding at a Glance

Tabular directives
8 Excludes2 · 1 use-additional code

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for R78 in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on R78 itself; “inherited from” names the category or block whose note applies here.

This page already reflects the FY2027 tabular note taking effect October 1, 2026.

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Use Additional Code

Supplementary codes the tabular list directs you to add.

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

Coder workflow for R78

MedCoder structured workflow — derived from this code’s own official record

Before you code R78

  1. R78 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).

    ReviewR78.0, R78.1, R78.2, R78.3, R78.4, R78.5, R78.6, R78.7, R78.8, R78.9

    See the relationships section · Guide: How to choose an ICD-10-CM code →

  2. Check whether an established diagnosis that explains this sign or symptom is documented. If one is, review whether the documented diagnosis changes the coding pathway: a symptom that is integral to a confirmed diagnosis is not reported separately, while one not routinely associated with it may be. Signs and symptoms are reported when no definitive diagnosis is established (Guidelines I.B.4, I.B.5, I.B.6, I.C.18.b).

    Guide: Symptom code vs confirmed diagnosis →

Choose the right path

  1. Does the documentation support one of the more specific codes beneath R78?
    Yes → Select that code and continue the checks below on its own page.
    No → R78 cannot be reported as written; query for the specificity its subcategory needs.

    ReviewR78.0, R78.1, R78.2, R78.3, R78.4, R78.5, R78.6, R78.7, R78.8, R78.9

  2. Is an established diagnosis that explains this sign or symptom documented?
    Yes → Review whether the documented diagnosis changes the coding pathway: a symptom integral to it is not reported separately.
    No → Continue — the sign or symptom code stands when no definitive diagnosis is established.

Consider R78. Then work the Use Additional Code note, and confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
The conditions the Use Additional Code note names
Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

Official instructions as workflow

  • Excludes2 — not part of R78(8 notes)

    Coding workflow: The conditions named in this note are not included in R78. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareO28, E78, D69

    See the official tabular notes · Guidelines I.A.12.b

  • Use Additional Code — after identifying R78(1 note)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with R78 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

    ReviewZ18

    See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: The sign or symptom is documented, and the same record establishes a diagnosis that routinely includes it.

Coding question: Is R78 reported in addition to the diagnosis?

Path: Review the documented diagnosis and whether the classification treats this finding as integral to it.

Reason: Signs and symptoms integral to a confirmed diagnosis are not coded separately; those not routinely associated with it may be reported when present (Guidelines I.B.5, I.B.6, I.C.18.b).

Documentation: A condition the Use Additional Code note names is documented.

Coding question: Is a second code reported with R78?

Path: Review the Use Additional Code note and the code it names.

Reason: The additional code is reported when the record documents the condition; a conditional instruction applies only when its condition is met (Guidelines I.A.13).

ReviewZ18

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Findings of drugs and other substances, not normally found in blood is a non-billable ICD-10-CM category code (R78). A more specific billable subcode must be selected for claims submission.

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Verify Before Coding

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name R78 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 8 Excludes2 notes: R83 — Abnormal findings in cerebrospinal fluid, R83-R89 — Abnormal findings on examination of other body fluids, substances and tissues, without diagnosis (R83-R89), R84 — Abnormal findings in specimens from respiratory organs and thorax, R85 — Abnormal findings in specimens from digestive organs and abdominal cavity, R86 — Abnormal findings in specimens from male genital organs, R87 — Abnormal findings in specimens from female genital organs, R88 — Abnormal findings in other body fluids and substances, R89 — Abnormal findings in specimens from other organs, systems and tissues.

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

Referenced by 1 Use Additional Code instruction: Z02.83 — Encounter for blood-alcohol and blood-drug test.

These codes instruct coders to additionally report this code when it applies.

Contextual Map

Every relationship of R78 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run R78 with these 18 related codes in Claim Check

Hierarchy

Excludes2 (32)

Use Additional Code

  • Z18 — Retained foreign body fragments[Use Additional Code]: “code to identify any retained foreign body, if applicable (Z18.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Excludes2 notes

Referenced by Use Additional Code instructions

Nearest codes (15)

Change history (3)

Common coding questions

Can R78 be billed directly?

No. R78 (Findings of drugs and other substances, not normally found in blood) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Change history

  • Upcoming · effective FY2027 — October 1, 2026
    Use Additional Code note will be added
    code to identify any retained foreign body, if applicable (Z18.-)
    FY2027 changes
  • Upcoming · effective FY2027 — October 1, 2026
    Use Additional Code note will be removed
    code to identify the any retained foreign body, if applicable (Z18.-)
    FY2027 changes
  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Findings of drugs and other substances, not normally found in blood

Nearest Codes in This Family

Official ICD-10-CM classifications closest to R78 in its code family, with their registry titles.