2026 ICD-10-CM Diagnosis Code Z49.31Encounter for adequacy testing for hemodialysis

ICD-10-CM Codes›Z00–Z99›Z40-Z53›Z49

ICD-10-CM Z49.31
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z49.31 is a billable ICD-10-CM diagnosis code for encounter for adequacy testing for hemodialysis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 698 through 700. The code is not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting. Coders also document this condition as adequacy of dialysis - finding. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Chronic kidney disease and Other aftercare encounter.

Code Identity

ICD-10-CM Code
Z49.31
Billable Status
Yes — Valid for Submission
Code Describes
Encounter for adequacy testing for hemodialysis
Short Description
Encounter for adequacy testing for hemodialysis
Same as the full description in the CMS dataset.
Parent Code
Z49.3
Encounter for adequacy testing for dialysis

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ40-Z53Encounters for other specific health care
CategoryZ49Encounter for care involving renal dialysis
This CodeZ49.31Encounter for adequacy testing for hemodialysis

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z49.31.

Unacceptable principal diagnosis
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.

Present on Admission (POA)Billing

Z49.31 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Adequacy of dialysis - finding
  • Adequacy of hemodialysis
  • Finding of measures of dialysis
  • Hemodialysis access site patent
  • Hemodialysis finding
  • Increase in hemodialysis blood flow
  • Increase in hemodialysis dialyzer size
  • Increase in hemodialysis session time

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Test, tests, testing(for)
      • adequacy (for dialysis)
        • hemodialysis

Clinical ClassificationClinical

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

CCSR GEN003
Chronic kidney disease
Default principal diagnosis: inpatient No · outpatient Yes
CCSR FAC010
Other aftercare encounter
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Dialysis

When your kidneys are healthy, they clean your blood. They also make hormones that keep your bones strong and your blood healthy. When your kidneys fail, you need treatment to replace the work your kidneys used to do. Unless you have a kidney transplant, you will need a treatment called dialysis.

Read the full article at MedlinePlus

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

Convert Z49.31 to ICD-9-CMHistory

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

ICD-9-CM
V56.31 Hemodialysis testing
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Z49.31Overview

Is Z49.31 (Encounter for adequacy testing for dialysis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report encounter for adequacy testing for hemodialysis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does Z49.31 group to?

On inpatient claims, encounter for adequacy testing for hemodialysis maps to MS-DRG 698, 699, 700, with relative weights from 0.6899 to 1.6544 depending on complications. Higher weights mean higher Medicare reimbursement.

Can Z49.31 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because encounter for adequacy testing for hemodialysis describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is Z49.31 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for encounter for adequacy testing for hemodialysis on inpatient claims.

What is the ICD-9 equivalent of Z49.31?

Under the General Equivalence Mappings, encounter for adequacy testing for hemodialysis converts to ICD-9-CM V56.31 (hemodialysis testing). The mapping is approximate, so confirm the match fits the documentation.