ICDcodes.org
FY2027

M84.559K — Pathological fracture in neoplastic disease, hip, unspecified, subsequent encounter for fracture with nonunion

BillableUnspecifiedCC

Is M84.559K billable?

Yes, but M84.559K will trip a Medicare edit. M84.559K is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, CMS lists M84.559K under Medicare Code Editor edit 20, “Unspecified code” — meaning a code specifying laterality (right, left or bilateral) exists in the same family. On an inpatient claim this triggers the edit, because CMS holds that there are very limited circumstances in which laterality cannot be documented.

M84.559K at a glance

CodeM84.559K
DescriptionPathological fracture in neoplastic disease, hip, unspecified, subsequent encounter for fracture with nonunion
BillableYes
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027
7th character "K"subsequent encounter for fracture with nonunion

What does the 7th character "K" mean in M84.559K?

In M84.559K, the 7th character K means subsequent encounter for fracture with nonunion. The 7th character is required for M84.559K to be a valid, complete code.

Same condition, different episode of care — switch the 7th character:

What Medicare edits apply to M84.559K?

The Medicare Code Editor screens inpatient claims before they are grouped. These edits name M84.559K directly.

Unspecified — a laterality-specific code exists — MCE edit 20

A code specifying laterality (right, left or bilateral) exists in the same family. CMS holds that there are very limited circumstances in which laterality cannot be documented.

Which MS-DRGs does M84.559K group to?

M84.559K sits in MDC 08 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

  • 521Hip Replacement with Principal Diagnosis of Hip Fracture with MCCsurgical
  • 522Hip Replacement with Principal Diagnosis of Hip Fracture without MCCsurgical

As a secondary diagnosis, M84.559K is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.

How is M84.559K listed in the Alphabetic Index?

The Alphabetic Index lists these routes under M84.559, the nearest indexed parent of M84.559K. Use them to find the family, then select the specific code.

  • Fracture, pathological › due to › neoplastic disease NEC › hip (pathologic)

Excludes2 — not included here — inherited from Chapter 13

The conditions below are not part of M84.559K, but a patient may have both at the same time. When documentation supports it, M84.559K and the excluded code may both be reported.

  • 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)

Excludes2 — not included here — inherited from M84

The conditions below are not part of M84.559K, but a patient may have both at the same time. When documentation supports it, M84.559K and the excluded code may both be reported.

  • traumatic fracture of bone-see fracture, by site

Code also — inherited from M84.5

Two codes may be needed to describe the condition fully. Whether M84.559K is sequenced first depends on the reason for the encounter.

  • underlying neoplasm

How long has M84.559K existed?

M84.559K has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.

Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.