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ICD-10-CM 2027 diagnosis code

M84.451APathological fracture, right femur, initial encounter for fracture

✓ Billable / specificRequires 7th characterCC — complication/comorbidity

M84.451A is a valid, billable ICD-10-CM code for pathological fracture, right femur, initial encounter for fracture. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Pathological fracture, right femur, init encntr for fracture

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About M84.451A

M84.451A is the ICD-10-CM diagnosis code for pathological fracture, right femur, initial encounter for fracture. It belongs to category M84 (disorder of continuity of bone), block M80-M85 (disorders of bone density and structure) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

The 7th character "A" means initial encounter for fracture: use it while the patient is receiving active treatment for the condition.

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 521 (Hip Replacement with Principal Diagnosis of Hip Fracture with MCC, relative weight 2.8515), DRG 522 (Hip Replacement with Principal Diagnosis of Hip Fracture without MCC, relative weight 2.1158), DRG 542 (Pathological Fractures and Musculoskeletal and Connective Tissue Malignancy with MCC, relative weight 1.7211), DRG 543 (Pathological Fractures and Musculoskeletal and Connective Tissue Malignancy with CC, relative weight 1.006), DRG 544 (Pathological Fractures and Musculoskeletal and Connective Tissue Malignancy without CC/MCC, relative weight 0.7406), DRG 791 (Prematurity with Major Problems, relative weight 4.1075) and 1 more, in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue) and MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 733.14 (pathologic fracture of neck of femur) and 733.15 (pathologic fracture of other specified part of femur).

7th character

Ainitial encounter for fracture

CC/MCC status for this injury by encounter: CC for A, K, P; Neither CC nor MCC for D, G, S.

Other encounter types for M84.451:

Notes that apply from higher levels

Instructions written at a parent level also apply to M84.451A.

› From M84.4 Pathological fracture, not elsewhere classified
Excludes1
  • collapsed vertebra NEC (M48.5)
  • pathological fracture in neoplastic disease (M84.5-)
  • pathological fracture in osteoporosis (M80.-)
  • pathological fracture in other disease (M84.6-)
  • stress fracture (M84.3-)
  • traumatic fracture (S12.-, S22.-, S32.-, S42.-, S52.-, S62.-, S72.-, S82.-, S92.-)
Excludes2
  • personal history of (healed) pathological fracture (Z87.311)
› From M84 Disorder of continuity of bone
Excludes2
  • traumatic fracture of bone-see fracture, by site

Broader instructions also apply from Chapter 13: Diseases of the musculoskeletal system and connective tissue.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

MDC 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period

MDC 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period

ICD-9-CM equivalent

Converter →
  • 733.14Pathologic fracture of neck of femurapproximate
  • 733.15Pathologic fracture of other specified part of femurapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about M84.451A

Is M84.451A billable?

Yes. M84.451A is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

What does the "A" at the end of M84.451A mean?

It is the 7th character for initial encounter for fracture. Per the official guidelines, use it while the patient is receiving active treatment for the condition.

Can M84.451A be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict M84.451A as a principal diagnosis.

Is M84.451A a CC or MCC?

M84.451A is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.

What DRG does M84.451A group to?

M84.451A is used in the MS-DRG v44.0 logic for MS-DRG 521 (Hip Replacement with Principal Diagnosis of Hip Fracture with MCC), MS-DRG 522 (Hip Replacement with Principal Diagnosis of Hip Fracture without MCC), MS-DRG 542 (Pathological Fractures and Musculoskeletal and Connective Tissue Malignancy with MCC), MS-DRG 543 (Pathological Fractures and Musculoskeletal and Connective Tissue Malignancy with CC), MS-DRG 544 (Pathological Fractures and Musculoskeletal and Connective Tissue Malignancy without CC/MCC), MS-DRG 791 (Prematurity with Major Problems) and 1 more. Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for M84.451A?

The CMS General Equivalence Mappings map M84.451A to ICD-9-CM 733.14 and 733.15.