2027 ICD-10-CM Diagnosis Code M84.329SStress fracture, unspecified humerus, sequela

ICD-10-CM Codes›M00–M99›M80-M85›M84

ICD-10-CM M84.329S
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

M84.329S is a billable ICD-10-CM diagnosis code for stress fracture, unspecified humerus, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 559 through 561. Coders also document this condition as stress fracture of humerus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pathological, stress and atypical fractures, sequela.

Code Identity

ICD-10-CM Code
M84.329S
Billable Status
Yes — Valid for Submission
Code Describes
Stress fracture, unspecified humerus, sequela
Short Description
Stress fracture, unspecified humerus, sequela
Same as the full description in the CMS dataset.
Parent Code
M84.329
Stress fracture, unspecified humerus

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM80-M85Disorders of bone density and structure
CategoryM84Disorder of continuity of bone
This CodeM84.329SStress fracture, unspecified humerus, sequela

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Stress fracture of humerus

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to M84.329S: its own notes plus those printed at M84.3, M84, and Chapter 13. A note printed at a category, block or chapter applies to every code under it.

Excludes1

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

From M84.3 Stress fracture applies to 228 codes

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 M84.3 Stress fracture applies to 228 codes
  • personal history of (healed) stress (fatigue) fracture (Z87.312)
  • stress fracture of vertebra (M48.4-)
From M84 Disorder of continuity of bone applies to 928 codes
  • traumatic fracture of bone-see fracture, by site
From Chapter 13 (M00-M99) Diseases of the musculoskeletal system and connective tissue applies to 6,687 codes
  • arthropathic psoriasis (L40.5-)
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • compartment syndrome (traumatic) (T79.A-)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Use Additional Code

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

From M84.3 Stress fracture applies to 228 codes
  • external cause code(s) to identify the cause of the stress fracture

Notes

General instructions on how these codes are used.

From Chapter 13 (M00-M99) Diseases of the musculoskeletal system and connective tissue applies to 6,687 codes
  • Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition

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 M84.3 Stress fracture applies to 228 codes
  • The appropriate 7th character is to be added to each code from subcategory M84.3:
Values for category M84.3 Pathological Fracture Encounter
  • Ainitial encounter for fracture
  • Dsubsequent encounter for fracture with routine healing
  • Gsubsequent encounter for fracture with delayed healing
  • Ksubsequent encounter for fracture with nonunion
  • Psubsequent encounter for fracture with malunion
  • Ssequela this code

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name M84.329S, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming M84.329S: they are not reported together with it, unless the two conditions are unrelated.

  • M84.4 Pathological fracture, not elsewhere classified
    stress fracture (M84.3-) names M84.3-, which includes this code

Clinical ClassificationClinical

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

CCSR MUS020
Pathological, stress and atypical fractures, sequela
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Fractures, Stress

    fractures due to the strain caused by repetitive exercise. they are thought to arise from a combination of muscle fatigue and bone failure, and occur in situations where bone remodeling predominates over repair. the most common sites of stress fractures are the metatarsus; fibula; tibia; and femoral neck.

Patient EducationClinical

Arm Injuries and Disorders

Of the 206 bones in your body, three of them are in your arm: the humerus, radius, and ulna. Your arms are also made up of muscles, joints, tendons, and other connective tissue. Injuries to any of these parts of the arm can occur during sports, a fall, or an accident.

Read the full article at MedlinePlus

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

Convert M84.329S to ICD-9-CMHistory

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

ICD-9-CM
905.2 Late effect arm fx
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About M84.329SOverview

What is the ICD-10 code for stress fracture, unspecified humerus, sequela?

The ICD-10-CM code for stress fracture, unspecified humerus, sequela is M84.329S (sometimes written as M84329S). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is M84.329S (Stress fracture, unspecified humerus) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report stress fracture, unspecified humerus, sequela on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character S in M84.329S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the stress fracture, unspecified humerus itself has resolved, not the original event.

What MS-DRG does M84.329S group to?

When stress fracture, unspecified humerus, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 559, 561, 560, with relative weights from 0.8258 to 1.8087 depending on complications. Higher weights mean higher Medicare reimbursement.

Can M84.329S be reported with a code from M84.4?

Not as a rule. The Excludes1 note at M84.3, which applies to M84.329S, lists "pathological fracture NOS (M84.4.-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).