2026 ICD-10-CM Diagnosis Code S50.829DBlister (nonthermal) of unspecified forearm, subsequent encounter

ICD-10-CM Codes›S00–T88›S50-S59›S50

ICD-10-CM S50.829D
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S50.829D is a billable ICD-10-CM diagnosis code for blister (nonthermal) of unspecified forearm, subsequent encounter. The 7th character D marks it as a subsequent encounter code, used during routine care in the healing or recovery phase. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 949 through 950. The code is exempt from POA reporting. Coders also document this condition as blister of forearm with infection. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Superficial injury; contusion, subsequent encounter.

Code Identity

ICD-10-CM Code
S50.829D
Billable Status
Yes — Valid for Submission
Code Describes
Blister (nonthermal) of unspecified forearm, subsequent encounter
Short Description
Blister (nonthermal) of unspecified forearm, subs encntr
Parent Code
S50.829
Blister (nonthermal) of unspecified forearm

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS50-S59Injuries to the elbow and forearm
CategoryS50Superficial injury of elbow and forearm
This CodeS50.829DBlister (nonthermal) of unspecified forearm, subsequent encounter

Present on Admission (POA)Billing

S50.829D 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.

  • Blister of forearm with infection
  • Blister of forearm without infection
  • Traumatic blister of forearm
  • Traumatic blister of forearm, infected

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Superficial injury of elbow and forearm (S50). 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.

CCSR INJ054
Superficial injury; contusion, subsequent encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Blisters

Blisters are fluid-filled sacs on the outer layer of your skin. They form because of rubbing, heat, or diseases of the skin. They are most common on your hands and feet.

The full article covers:

  • What are blisters?
  • What causes blisters?
  • What are the treatments for blisters?
  • Can blisters be prevented?

Read the full article at MedlinePlus

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

Convert S50.829D to ICD-9-CMHistory

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

ICD-9-CM
V58.89 Other specfied aftercare
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 S50.829DOverview

Is S50.829D (Blister (nonthermal) of unspecified forearm) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report blister (nonthermal) of unspecified forearm, subsequent encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character D in S50.829D mean?

The final character D marks a subsequent encounter: use it for routine care while the blister (nonthermal) of unspecified forearm is healing, after active treatment has ended.

What MS-DRG does S50.829D group to?

When blister (nonthermal) of unspecified forearm, subsequent encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 949, 950, with relative weights from 0.6277 to 1.1897 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S50.829D 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 blister (nonthermal) of unspecified forearm, subsequent encounter on inpatient claims.

What is the ICD-9 equivalent of S50.829D?

Under the General Equivalence Mappings, blister (nonthermal) of unspecified forearm, subsequent encounter converts to ICD-9-CM V58.89 (other specfied aftercare). 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.