2027 ICD-10-CM Diagnosis Code M84.345AStress fracture, left finger(s), initial encounter for fracture

ICD-10-CM Codes›M00–M99›M80-M85›M84

ICD-10-CM M84.345A
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

M84.345A is a billable ICD-10-CM diagnosis code for stress fracture, left finger(s), initial encounter for fracture. The 7th character A means initial encounter for fracture, 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 542 through 544. Coders also document this condition as stress fracture of finger of left hand. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Stress fracture, initial encounter.

Code Identity

ICD-10-CM Code
M84.345A
Billable Status
Yes — Valid for Submission
Code Describes
Stress fracture, left finger(s), initial encounter for fracture
Short Description
Stress fracture, left finger(s), init encntr for fracture
Parent Code
M84.345
Stress fracture, left finger(s)

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM80-M85Disorders of bone density and structure
CategoryM84Disorder of continuity of bone
This CodeM84.345AStress fracture, left finger(s), initial encounter for fracture

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Stress fracture of finger of left hand
  • Stress fracture of hand
  • Stress fracture of left hand

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to M84.345A: 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 this code
  • 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

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name M84.345A, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming M84.345A: 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 MUS016
Stress fracture, initial encounter
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

Finger Injuries and Disorders

You use your fingers and thumbs to do everything from grasping objects to playing musical instruments to typing. When there is something wrong with them, it can make life difficult. Common problems include:

Read the full article at MedlinePlus

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

Convert M84.345A to ICD-9-CMHistory

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

ICD-9-CM
733.95 Stress fracture bone NEC
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 M84.345AOverview

What is the ICD-10 code for stress fracture, left finger(s), initial encounter for fracture?

The ICD-10-CM code for stress fracture, left finger(s), initial encounter for fracture is M84.345A (sometimes written as M84345A). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is M84.345A (Stress fracture, left finger(s)) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report stress fracture, left finger(s), initial encounter for fracture on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in M84.345A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for stress fracture, left finger(s), such as an emergency visit or first evaluation. In this category the CMS Tabular List defines A as "initial encounter for fracture".

What MS-DRG does M84.345A group to?

When stress fracture, left finger(s), initial encounter for fracture is the principal diagnosis on an inpatient stay, it groups to MS-DRG 543, 544, 542, with relative weights from 0.7404 to 1.7208 depending on complications. Higher weights mean higher Medicare reimbursement.

Can M84.345A be reported with a code from M84.4?

Not as a rule. The Excludes1 note at M84.3, which applies to M84.345A, 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).