2026 ICD-10-CM Diagnosis Code T50.1X5AAdverse effect of loop [high-ceiling] diuretics, initial encounter
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 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 917 through 918. The code is not accepted as a principal diagnosis by the Medicare Code Editor. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Adverse effects of drugs and medicaments, initial encounter.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for T50.1X5A.
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 2026, published by CMS and the National Center for Health Statistics.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Bumetanide
a sulfamyl diuretic.Sodium Potassium Chloride Symporter Inhibitors
agents that inhibit sodium-potassium-chloride symporters which are concentrated in the thick ascending limb at the junction of the loop of henle and kidney tubules, distal. they act as diuretics. excess use is associated with hypokalemia and hyperglycemia.Solute Carrier Family 12, Member 1
na-k-cl transporter in the ascending limb of loop of henle. it mediates active reabsorption of sodium chloride and is inhibited by loop diuretics such as furosemide; and bumetanide. mutations in the gene encoding slc12a1 are associated with a bartter syndrome.Solute Carrier Family 12, Member 2
na-k-cl transporter ubiquitously expressed. it plays a key role in salt secretion in epithelial cells and cell volume regulation in nonepithelial cells.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.
| Substance | Accidental | Self-harm | Assault | Undetermined | Adverse Effect | Underdosing |
|---|---|---|---|---|---|---|
| Bumetanide | T50.1X1 | T50.1X2 | T50.1X3 | T50.1X4 | T50.1X5 | T50.1X6 |
| Edecrin | T50.1X1 | T50.1X2 | T50.1X3 | T50.1X4 | T50.1X5 | T50.1X6 |
| Etacrynate sodium | T50.1X1 | T50.1X2 | T50.1X3 | T50.1X4 | T50.1X5 | T50.1X6 |
| Etacrynic acid | T50.1X1 | T50.1X2 | T50.1X3 | T50.1X4 | T50.1X5 | T50.1X6 |
| Ethacrynic acid | T50.1X1 | T50.1X2 | T50.1X3 | T50.1X4 | T50.1X5 | T50.1X6 |
| Etozolin | T50.1X1 | T50.1X2 | T50.1X3 | T50.1X4 | T50.1X5 | T50.1X6 |
| Frusemide | T50.1X1 | T50.1X2 | T50.1X3 | T50.1X4 | T50.1X5 | T50.1X6 |
| Furosemide | T50.1X1 | T50.1X2 | T50.1X3 | T50.1X4 | T50.1X5 | T50.1X6 |
| Lasix | T50.1X1 | T50.1X2 | T50.1X3 | T50.1X4 | T50.1X5 | T50.1X6 |
| Lyovac Sodium Edecrin | T50.1X1 | T50.1X2 | T50.1X3 | T50.1X4 | T50.1X5 | T50.1X6 |
| Piretanide | T50.1X1 | T50.1X2 | T50.1X3 | T50.1X4 | T50.1X5 | T50.1X6 |
| Ticrynafen | T50.1X1 | T50.1X2 | T50.1X3 | T50.1X4 | T50.1X5 | T50.1X6 |
| Tienilic acid | T50.1X1 | T50.1X2 | T50.1X3 | T50.1X4 | T50.1X5 | T50.1X6 |
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.
Code HistoryHistory
Questions About T50.1X5AOverview
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, 2025 through September 30, 2026.
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 917, 918, with relative weights from 0.8571 to 1.5684 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.
What is the ICD-9 equivalent of T50.1X5A?
Under the General Equivalence Mappings, adverse effect of loop [high-ceiling] diuretics, initial encounter converts to ICD-9-CM 995.29 (adv eff med/biol NEC/NOS) and E944.4 (adv eff diuretics NEC). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
