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T45.2X6S vs T46.7

T45.2X6S (Underdosing of vitamins, sequela) compared with T46.7 (Poisoning by, adverse effect of and underdosing of peripheral vasodilators), from the official CMS tabular data.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources

Summary

These codes can be reported together when both conditions are documented, because T45.2X6S lists T46.7 under Excludes2, which marks them as distinct conditions.

Official rule
What is different?

The conditions named and billing status.T45.2X6S is “Underdosing of vitamins, sequela”; T46.7 is “Poisoning by, adverse effect of and underdosing of peripheral vasodilators”. T46.7 is a non-billable header; T45.2X6S is billable.

Registry fact

Can these codes be reported together?

Yes, when both are documented.T45.2X6S lists T46.7 under Excludes2: “poisoning by, adverse effect of and underdosing of nicotinic acid (derivatives) (T46.7)”. Excludes2 marks distinct conditions that may both be reported when both are documented.

Official ruleGuide: Excludes1 vs Excludes2

Is there an Excludes1 relationship?

None.Neither entry carries an Excludes1 note that names the other code. T45.2X6S carries 2 Excludes1 notes and T46.7 carries 3 Excludes1 notes covering other codes; the side-by-side table quotes them.

Official rule

Is there an Excludes2 relationship?

Yes.T45.2X6S’s tabular entry: “poisoning by, adverse effect of and underdosing of nicotinic acid (derivatives) (T46.7)”. The note covers T46.7.

Official ruleGuide: Excludes1 vs Excludes2

Is one more specific?

Not comparable.The codes sit in different categories; specificity is only comparable within one category.

Is one a parent or header code?

One is a header.T46.7 is a non-billable header, but T45.2X6S is not one of its subdivisions.

Registry fact

Are there sequencing instructions?

None.Neither entry carries a Code First or Use Additional Code note that names the other.

Official rule

Are there other coding relationships?

None found.No laterality, encounter-phase, Table of Neoplasms, Table of Drugs and Chemicals, or history-versus-active-disease relationship links these codes.

MedCoder-derived

Official rule: a tabular instructional note or a section of the ICD-10-CM Official Guidelines, quoted as published. Registry fact: the codes’ own published attributes (titles, billable status, position in the hierarchy, code set). MedCoder-derived: a reading MedCoder computes from those facts; it is not itself a rule. How to read the labels

Can these codes be reported together?

Informational

Excludes2 relationship

T45.2X6S
Underdosing of vitamins, sequela
↔
T46.7
Poisoning by, adverse effect of and underdosing of peripheral vasodilators

What we found

Yes, when both are documented.T45.2X6S carries an Excludes2 note covering T46.7: “poisoning by, adverse effect of and underdosing of nicotinic acid (derivatives) (T46.7)”

Excludes2 marks distinct conditions — both may be reported when both are documented.

What to review

Report both only when the documentation supports both conditions; otherwise report the one documented.

Guide: Excludes1 vs Excludes2Check these on a claim

Why it matters

An Excludes2 note means the excluded condition is not part of the code above it, but a patient can have both. Report both when both are documented.

Source / rule

CMS ICD-10-CM tabular instructional notes

Official guidance behind these answers

  • Section I.A.12.b — Excludes2 · applies to: Excludes2

    A type 2 Excludes note represents “Not included here.” An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

    ICD-10-CM Official Guidelines FY2027

Quoted from the ICD-10-CM Official Guidelines for Coding and Reporting in effect for the release shown. The tabular notes above are the code-level instruction; these sections are the convention that says how such a note is applied. Source document (CMS PDF) · Release and checksum

Side by side

Similar descriptions do not make codes interchangeable. The documentation and the official instructions decide which code applies.

Official descriptionDiffers
T45.2X6S

Underdosing of vitamins, sequela

T46.7

Poisoning by, adverse effect of and underdosing of peripheral vasodilators

StatusDiffers
T45.2X6S
Billable
T46.7
Non-billable header

A header is not reported on a claim; a code beneath it is.

Report instead: T46.7X1A, T46.7X1D, T46.7X1S, T46.7X2A, T46.7X2D

Excludes1Differs
T45.2X6S
  • vitamin deficiencies (E50-E56)
  • toxic reaction to local anesthesia in pregnancy (O29.3-)
T46.7
  • poisoning by, adverse effect of and underdosing of papaverine (T44.3)
  • poisoning by, adverse effect of and underdosing of metaraminol (T44.4)
  • toxic reaction to local anesthesia in pregnancy (O29.3-)
Excludes2Differs
T45.2X6S
  • poisoning by, adverse effect of and underdosing of nicotinic acid (derivatives) (T46.7)
  • poisoning by, adverse effect of and underdosing of iron (T45.4)
  • poisoning by, adverse effect of and underdosing of vitamin K (T45.7)
  • abuse and dependence of psychoactive substances (F10-F19)
  • abuse of non-dependence-producing substances (F55.-)
  • immunodeficiency due to drugs (D84.821)
  • drug reaction and poisoning affecting newborn (P00-P96)
  • pathological drug intoxication (inebriation) (F10-F19)
T46.7
  • abuse and dependence of psychoactive substances (F10-F19)
  • abuse of non-dependence-producing substances (F55.-)
  • immunodeficiency due to drugs (D84.821)
  • drug reaction and poisoning affecting newborn (P00-P96)
  • pathological drug intoxication (inebriation) (F10-F19)
Code firstSame for both
  • , for adverse effects, the nature of the adverse effect, such as:
  • adverse effect NOS (T88.7)
Use additional codeSame for both
  • code(s) to specify:
  • manifestations of poisoning
  • underdosing or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9)
CategoryDiffers
T45.2X6S

T45 Poisoning by, adverse effect of and underdosing of primarily systemic and hematological agents, not elsewhere classified

T46.7

T46 Poisoning by, adverse effect of and underdosing of agents primarily affecting the cardiovascular system

ChapterSame for both

S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)

IncludesSame for both
  • adverse effect of correct substance properly administered
  • poisoning by overdose of substance
  • poisoning by wrong substance given or taken in error
  • underdosing by (inadvertently) (deliberately) taking less substance than prescribed or instructed
7th characterDiffers
T45.2X6S
  • The appropriate 7th character is to be added to each code from category T45
T46.7
  • The appropriate 7th character is to be added to each code from category T46

No Code also note at either code.

Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on. In a row that differs, notes every code shares are dimmed.

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Derived from the official CMS ICD-10-CM tabular data (FY2027). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources