2027 ICD-10-CM Diagnosis Code T50.1X5AAdverse effect of loop [high-ceiling] diuretics, initial encounter

ICD-10-CM Codes›S00–T88›T36-T50›T50

ICD-10-CM T50.1X5A
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

T50.1X5A is a billable ICD-10-CM diagnosis code for adverse effect of loop [high-ceiling] diuretics, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 791, 793, 917 through 918. The code is not accepted as a principal diagnosis by the Medicare Code Editor. Coders also document this condition as adverse reaction to saluretic agent. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Adverse effects of drugs and medicaments, initial encounter.

Code Identity

ICD-10-CM Code
T50.1X5A
Billable Status
Yes — Valid for Submission
Code Describes
Adverse effect of loop [high-ceiling] diuretics, initial encounter
Short Description
Adverse effect of loop diuretics, initial encounter
Parent Code
Adverse effect of loop [high-ceiling] diuretics

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT36-T50Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
CategoryT50Poisoning by, adverse effect of and underdosing of diuretics and other and unspecified drugs, medicaments and biological substances
This CodeT50.1X5AAdverse effect of loop [high-ceiling] diuretics, initial encounter

Code EditsBilling

Medicare Code Editor checks that affect claim validity for T50.1X5A.

There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Adverse reaction to saluretic agent
  • Bumetanide adverse reaction
  • Ethacrynic acid adverse reaction
  • Furosemide adverse reaction
  • Loop diuretic adverse reaction
  • Pesticide adverse reaction
  • Piretanide adverse reaction
  • Sulfonamide diuretic adverse reaction
  • Torasemide adverse reaction

Coding GuidelinesGuidance

When coding an adverse effect of a drug that has been correctly prescribed and properly administered, assign the appropriate code for the nature of the adverse effect followed by the appropriate code for the adverse effect of the drug.

The appropriate 7th character is to be added to each code from block Poisoning by, adverse effect of and underdosing of diuretics and other and unspecified drugs, medicaments and biological substances (T50). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to T50.1X5A: its own notes plus those printed at T50, block T36-T50, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • 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

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • toxic reaction to local anesthesia in pregnancy (O29.3-)

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.

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • 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)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Code First

The underlying condition named in the note is sequenced before this code.

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • for adverse effects, the nature of the adverse effect, such as:
  • adverse effect NOS (T88.7)
  • aspirin gastritis (K29.-)
  • blood disorders (D56-D76)
  • contact dermatitis (L23-L25)
  • dermatitis due to substances taken internally (L27.-)
  • nephropathy (N14.0-N14.2)

Use Additional Code

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

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • code(s) to specify:
  • manifestations of poisoning
  • underdosing or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9)
  • underdosing of medication regimen (Z91.12-, Z91.13-)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Notes

General instructions on how these codes are used.

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • The drug giving rise to the adverse effect should be identified by use of codes from categories T36-T50 with fifth or sixth character 5.
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

From T50 Poisoning by, adverse effect of and underdosing of diuretics and other and unspecified drugs, medicaments and biological substances applies to 342 codes
  • The appropriate 7th character is to be added to each code from category T50
  • Ainitial encounter this code
  • Dsubsequent encounter
  • Ssequela

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name T50.1X5A, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming T50.1X5A: its condition is not part of those codes, and both may be reported when the patient has both.

  • T46.5 Poisoning by, adverse effect of and underdosing of other antihypertensive drugs
    poisoning by, adverse effect of and underdosing of diuretics (T50.0-T50.2) names T50.0-T50.2, which includes this code

Use Additional Code 1

These codes say to use an additional code from the note, and T50.1X5A is one of the codes named.

  • G61.1 Serum neuropathy
    code for adverse effect, if applicable, to identify serum (T50.-) names T50.-, which includes this code

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ028
Adverse effects of drugs and medicaments, initial encounter
Default principal diagnosis: inpatient No · outpatient Yes

Clinical InformationClinical

  • Bumetanide

    a sulfamyl diuretic.
  • Ethacrynic Acid

    a compound that inhibits symport of sodium, potassium, and chloride primarily in the ascending limb of henle, but also in the proximal and distal tubules. this pharmacological action results in excretion of these ions, increased urinary output, and reduction in extracellular fluid. this compound has been classified as a loop or high ceiling diuretic.
  • Furosemide

    a benzoic-sulfonamide-furan. it is a diuretic with fast onset and short duration that is used for edema and chronic renal insufficiency.
  • Ticrynafen

    a novel diuretic with uricosuric action. it has been proposed as an antihypertensive agent.

Table of Drugs and ChemicalsClinical

Substances in the Table of Drugs and Chemicals that reference this code family. Always confirm in the Tabular List before coding.

SubstanceAccidentalSelf-harmAssaultUndeter­minedAdverse
Effect
Under­dosing
BumetanideT50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6
Diuretic NEC::loop (high-ceiling)T50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6
EdecrinT50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6
Etacrynate sodiumT50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6
Etacrynic acidT50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6
Ethacrynic acidT50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6
EtozolinT50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6
FrusemideT50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6
FurosemideT50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6
LasixT50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6
Lyovac Sodium EdecrinT50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6
PiretanideT50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6
Sodium::ethacrynateT50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6
TicrynafenT50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6
Tienilic acidT50.1X1T50.1X2T50.1X3T50.1X4T50.1X5T50.1X6

Patient EducationClinical

Drug Reactions

Most of the time, medicines make our lives better. They reduce aches and pains, fight infections, and control problems such as high blood pressure or diabetes. But medicines can also cause unwanted reactions, such as drug interactions, side effects, and allergies.

The full article covers:

  • What is a drug interaction?
  • What are side effects?
  • What are drug allergies?
  • How can I stay safe when taking medicines?

Read the full article at MedlinePlus

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

Convert T50.1X5A to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
995.29 Adv eff med/biol NEC/NOS
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
E944.4 Adv eff diuretics NEC
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

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 T50.1X5AOverview

What is the ICD-10 code for adverse effect of loop [high-ceiling] diuretics, initial encounter?

The ICD-10-CM code for adverse effect of loop [high-ceiling] diuretics, initial encounter is T50.1X5A (sometimes written as T501X5A). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is T50.1X5A (Adverse effect of loop [high-ceiling] diuretics) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report adverse effect of loop [high-ceiling] diuretics, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in T50.1X5A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for adverse effect of loop [high-ceiling] diuretics, such as an emergency visit or first evaluation.

What MS-DRG does T50.1X5A group to?

On inpatient claims, adverse effect of loop [high-ceiling] diuretics, initial encounter maps to MS-DRG 793, 791, 918, 917, with relative weights from 0.8716 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.

Can T50.1X5A be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because adverse effect of loop [high-ceiling] diuretics, initial encounter describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.