2027 ICD-10-CM Diagnosis Code M84.471APathological fracture, right ankle, initial encounter for fracture
ICD-10-CM Codes›M00–M99›M80-M85›M84
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- 7th Character A — Initial Encounter for Fracture
- Not Chronic
M84.471A is a billable ICD-10-CM diagnosis code for pathological fracture, right ankle, 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, 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. Coders also document this condition as pathological fracture of ankle. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pathological fracture, initial encounter.
M84.471A does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 87 for payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
M84.471A does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.
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.
- Pathological fracture of ankle
- Pathological fracture of right ankle
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to M84.471A: 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.
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.
- personal history of (healed) pathological fracture (Z87.311)
- traumatic fracture of bone-see fracture, by site
- 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.
- 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.
- The appropriate 7th character is to be added to each code from subcategory M84.4:
- 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 M84.471A, its category, or a range that includes it.
Excludes1 4
These codes carry an Excludes1 note naming M84.471A: they are not reported together with it, unless the two conditions are unrelated.
- M48.4 Fatigue fracture of vertebrapathological fracture NOS (M84.4-) names M84.4-, which includes this code
- M48.5 Collapsed vertebra, not elsewhere classifiedpathological fracture NOS (M84.4-) names M84.4-, which includes this code
- M80 Osteoporosis with current pathological fracturepathological fracture NOS (M84.4) names M84.4, which includes this code
- M84.3 Stress fracturepathological fracture NOS (M84.4.-) names M84.4.-, which includes this code
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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
Ankle Injuries and Disorders
Your ankle bone and the ends of your two lower leg bones make up the ankle joint. Your ligaments, which connect bones to one another, stabilize and support it. Your muscles and tendons move it.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert M84.471A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M84.471AOverview
What is the ICD-10 code for pathological fracture, right ankle, initial encounter for fracture?
The ICD-10-CM code for pathological fracture, right ankle, initial encounter for fracture is M84.471A (sometimes written as M84471A). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is M84.471A (Pathological fracture, right ankle) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report pathological fracture, right ankle, initial encounter for fracture on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What does the 7th character A in M84.471A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for pathological fracture, right ankle, 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 M84.471A group to?
When pathological fracture, right ankle, initial encounter for fracture is the principal diagnosis on an inpatient stay, it groups to MS-DRG 543, 793, 791, 544, 542, with relative weights from 0.7404 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.
Is M84.471A a CC or MCC?
CMS lists M84.471A 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.
Does M84.471A risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage: M84.471A maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 87 (Osteoporosis, Vertebral and Pathological Fractures).
