2027 ICD-10-CM Diagnosis Code M84.453APathological fracture, unspecified femur, initial encounter for fracture

ICD-10-CM Codes›M00–M99›M80-M85›M84

ICD-10-CM M84.453A
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

M84.453A is a billable ICD-10-CM diagnosis code for pathological fracture, unspecified femur, 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 521 through 522, 542 through 544, 791, 793. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 214 closely related codes. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family. Coders also document this condition as osteoporotic fracture of bone of hip region. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pathological fracture, initial encounter.

For Medicare Advantage risk adjustment, M84.453A maps to CMS-HCC Category 402 (Hip Fracture/Dislocation) under the V28 model, adding a risk factor of about 0.467 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
M84.453A
Billable Status
Yes — Valid for Submission
Code Describes
Pathological fracture, unspecified femur, initial encounter for fracture
Short Description
Pathological fracture, unsp femur, init encntr for fracture
Parent Code
M84.453
Pathological fracture, unspecified femur

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM80-M85Disorders of bone density and structure
CategoryM84Disorder of continuity of bone
This CodeM84.453APathological fracture, unspecified femur, initial encounter for fracture

Code EditsBilling

Medicare Code Editor checks that affect claim validity for M84.453A.

Unspecified codes
Unspecified codes exist in the ICD-10-CM classification for circumstances when documentation in the medical record does not provide the level of detail needed to support reporting a more specific code. However, in the inpatient setting, there should generally be very limited and rare circumstances for which the laterality (right, left, bilateral) of a condition is unable to be documented and reported. The following pages contain the list of unspecified ICD-10-CM diagnosis codes for which there is a more specific code to identify laterality (right, left, bilateral) within that code family.

Medicare Risk Adjustment (HCC)Billing

M84.453A maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.

CMS-HCC V28 Category (Payment Model)
HCC 402— Hip Fracture/Dislocation
Payment HCC · PY 2027 one of 729 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.467
community, non-dual, aged · ranges 0.089–0.570 across segments
Hierarchy
Top of its hierarchy
HCC 402 is not superseded by any other condition category
Prior Model (CMS-HCC V24)
HCC 170
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 170 · ESRD (V21): HCC 170 · ESRD (V24): HCC 170
ESRD V21 weights: 0.050 dialysis, 0.000–0.350 functioning graft · ESRD V24 weights: 0.063 dialysis, 0.000–0.430 functioning graft
Part D (RxHCC)
RxHCC 87 — Osteoporosis, Vertebral and Pathological Fractures
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Osteoporotic fracture of bone of hip region
  • Osteoporotic fracture of femur
  • Osteoporotic fracture of neck of femur
  • Osteoporotic fracture of proximal femur
  • Pathological fracture of femur
  • Pathological fracture of neck of femur
  • Pathological fracture of pelvis
  • Pathological fracture of pelvis and femur
  • Pathological fracture of proximal end of femur
  • Stress fracture of neck of femur

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to M84.453A: its own notes plus those printed at M84.4, 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 M84.4 Pathological fracture, not elsewhere classified 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 M84.4 Pathological fracture, not elsewhere classified applies to 228 codes
  • personal history of (healed) pathological fracture (Z87.311)
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)

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 M84.4 Pathological fracture, not elsewhere classified applies to 228 codes
  • The appropriate 7th character is to be added to each code from subcategory M84.4:
Values for category M84.4 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 M84.453A, its category, or a range that includes it.

Excludes1 4

These codes carry an Excludes1 note naming M84.453A: they are not reported together with it, unless the two conditions are unrelated.

  • M48.4 Fatigue fracture of vertebra
    pathological fracture NOS (M84.4-) names M84.4-, which includes this code
  • M48.5 Collapsed vertebra, not elsewhere classified
    pathological fracture NOS (M84.4-) names M84.4-, which includes this code
  • M80 Osteoporosis with current pathological fracture
    pathological fracture NOS (M84.4) names M84.4, which includes this code
  • M84.3 Stress fracture
    pathological fracture NOS (M84.4.-) names M84.4.-, which includes this code

Clinical ClassificationClinical

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

CCSR MUS014
Pathological fracture, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Fractures, Spontaneous

    fractures occurring as a result of disease of a bone or from some undiscoverable cause, and not due to trauma. (dorland, 27th ed)

Patient EducationClinical

Fractures

A fracture is a break in a bone. Fractures are usually caused by injuries. Since they can sometimes be serious, it's important to get medical care right away if you think you have a fracture.

The full article covers:

  • What is a fracture?
  • What are the different types of fractures?
  • What causes fractures?
  • What are the symptoms of a fracture?
  • How are fractures diagnosed?
  • What are the treatments for fractures?
  • Can fractures be prevented?

Read the full article at MedlinePlus

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

Convert M84.453A to ICD-9-CMHistory

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

ICD-9-CM
733.15 Path fx oth spcf prt fmr
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 M84.453AOverview

Is M84.453A (Pathological fracture, unspecified femur) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report pathological fracture, unspecified femur, initial encounter for fracture on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in M84.453A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for pathological fracture, unspecified femur, 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 M84.453A group to?

When pathological fracture, unspecified femur, initial encounter for fracture is the principal diagnosis on an inpatient stay, it groups to MS-DRG 543, 793, 791, 521, 544, 522, 542, with relative weights from 0.7404 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.

Is M84.453A a CC or MCC?

CMS lists M84.453A as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 214 closely related codes in its exclusion list.

Can M84.453A be reported with M48.5?

Not as a rule. The Excludes1 note at M84.4, which applies to M84.453A, lists "collapsed vertebra NEC (M48.5)". 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).

What HCC is M84.453A?

M84.453A (pathological fracture, unspecified femur, initial encounter for fracture) maps to CMS-HCC Category 402 (Hip Fracture/Dislocation), commonly written as HCC 402, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 170 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 87.

Does M84.453A risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, M84.453A adds a risk adjustment factor of about 0.467 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.089 to 0.570 depending on the payment segment). HCC 402 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 402 category page.