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M84.58XK ICD-10-CM Code: Pathological fracture in neoplastic disease, other specified site, subsequent encounter for fracture with nonunion

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

7th character
Required — see the character table on this page
Tabular directives
1 inclusion term · 1 Excludes2 · 1 code-also instruction

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 564 — OTHER MUSCULOSKELETAL SYSTEM AND CONNECTIVE TISSUE DIAGNOSES WITH MCC (MDC 08)
  • MS-DRG 565 — OTHER MUSCULOSKELETAL SYSTEM AND CONNECTIVE TISSUE DIAGNOSES WITH CC (MDC 08)
  • MS-DRG 566 — OTHER MUSCULOSKELETAL SYSTEM AND CONNECTIVE TISSUE DIAGNOSES WITHOUT CC/MCC (MDC 08)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for M84.58XK in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on M84.58XK itself; “inherited from” names the category or block whose note applies here.

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Pathological fracture in neoplastic disease, vertebrae

Source: inherited from M84.58

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

  • traumatic fracture of bone-see fracture, by site

Source: inherited from M84

Code Also

Additional codes that may be required to fully describe the encounter.

  • underlying neoplasm

Source: inherited from M84.5

7th Character Guide

"The appropriate 7th character is to be added to each code from subcategory M84.5:"

  • A — initial encounter for fracture
  • D — subsequent encounter for fracture with routine healing
  • G — subsequent encounter for fracture with delayed healing
  • K — subsequent encounter for fracture with nonunion (this page’s code)
  • P — subsequent encounter for fracture with malunion
  • S — sequela

How the encounter character is assigned. “Initial encounter” means the patient is receiving active treatment for the condition — it is not limited to the first visit, and a different or new provider giving active treatment still assigns it. “Subsequent encounter” covers care during the healing or recovery phase after active treatment. “Sequela” is for complications or conditions that arise as a direct result of the original condition.

ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19.a (paraphrased by MedCoder).

Variant codes in this family

M84.58XA, M84.58XD, M84.58XG, M84.58XK, M84.58XP, M84.58XS

Character meanings are CMS's official 7th-character extensions for this family, as carried in each variant code's official description; variant codes are registry rows. The explanation of how the encounter character is assigned is MedCoder editorial, distinct from the official content above it.

Coder workflow for M84.58XK

MedCoder structured workflow — derived from this code’s own official record

Before you code M84.58XK

  1. “Other” (NEC) means the condition is specified in the record but no dedicated code captures it. Confirm the documented form is not one a sibling code names before settling on M84.58XK; if the record states no specifics at all, the unspecified sibling applies instead. “Other” codes are for documented conditions the classification gives no specific code; “unspecified” codes are for records lacking the detail (Guidelines I.A.9.a, I.A.9.b).

    See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

  2. A 7th character is required in this family. Confirm the documented encounter: initial (active treatment), subsequent (healing or recovery phase), or sequela. This page’s code carries “K”. “Initial” means active treatment, not the first visit (Guidelines I.C.19.a).

    See the 7th Character Guide · Guide: 7th characters: initial, subsequent, sequela →

  3. M84.58XK’s title joins a condition with an associated condition or complication. Confirm each component is documented. Where the classification presumes the link through the “with” convention, only a provider statement that the conditions are unrelated defeats it. A combination code is assigned only when it fully identifies the documented conditions; a required second code for the stage, type or manifestation is still reported when the notes ask for it (Guidelines I.B.9, I.A.15).

    Guide: Combination codes →

Choose the right path

  1. Is the encounter phase documented — active treatment, healing or recovery, or a sequela?
    Yes → Assign the matching 7th character; the variant codes are in the 7th Character Guide.
    No → The code is invalid without its 7th character — query for the missing element.

Consider M84.58XK. Then review the Code Also note, and confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Encounter type
Active treatment, healing or recovery phase, or sequela — the basis of the 7th character (Guidelines I.C.19.a).
The associated condition or complication
Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).
Open or closed; displaced or nondisplaced
Defaults apply when the record is silent: closed, and displaced (Guidelines I.C.19.c).
Any detail beyond this code’s title
What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

  • Excludes2 — not part of M84.58XK(1 note)

    Coding workflow: The conditions named in this note are not included in M84.58XK. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    See the official tabular notes · Guidelines I.A.12.b

  • Code Also — related condition(1 note)

    Coding workflow: Review the related condition when both are documented and the instruction applies. A Code Also note does not fix sequencing; the order follows the circumstances of the encounter.

    See the official tabular notes · Guidelines I.A.17

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: The patient returns during the healing or recovery phase after active treatment of the same condition.

Coding question: Which 7th character applies?

Path: Review the official 7th-character definitions for this family in the 7th Character Guide.

Reason: “Initial encounter” means active treatment, not the first visit; care during recovery takes “subsequent encounter”, and a complication arising from the original condition takes “sequela” (Guidelines I.C.19.a).

Documentation: Only one of the components this code’s title joins is documented.

Coding question: Is M84.58XK supported?

Path: Review the code for the documented component on its own.

Reason: A combination code is assigned only when it fully identifies the documented conditions; otherwise the documented component takes its own code (Guidelines I.B.9).

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Pathological fracture in neoplastic disease, other specified site, subsequent encounter for fracture with nonunion is a billable ICD-10-CM diagnosis code (M84.58XK).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Official Coding Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Verbatim excerpts from the ICD-10-CM Official Guidelines for Coding and Reporting (CMS/NCHS) that govern this code.

Chapter 2: Neoplasms (C00-D49 )

6) Pathologic fracture due to a neoplasm When an encounter is for a pathological fracture due to a neoplasm, and the focus of treatment is the fracture, a code from subcategory M84.5, Pathological fracture in neoplastic disease, should be sequenced first, followed by the code for the neoplasm.

Chapter 2: Neoplasms (C00-D49 )

If the focus of treatment is the neoplasm with an associated pathological fracture, the neoplasm code should be sequenced first, followed by a code from M84.5 for the pathological fracture.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

  1. A 7th character applies in this family. Confirm the documented encounter matches the character assigned. See the official 7th-character definitions and this code’s variants
  2. 1 Code Also note — a second code may apply; the guidelines leave its sequencing to the circumstances of the encounter. See the Code Also notes
  3. 1 Excludes2 entry — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name M84.58XK or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: M84.4 — Pathological fracture, not elsewhere classified (via M84.5.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

Not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity.

Named in the grouper logic of 3 MS-DRGs: DRG 564 (MDC 08), DRG 565 (MDC 08), DRG 566 (MDC 08).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):MUS015 — Pathological fracture, subsequent encounter (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Pathological fracture, subsequent encounter).

+623 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Collapse”; these codes share that main term but sit in a different category of the Tabular List.

M48.50 — Collapsed vertebra, not elsewhere classified, site unspecified (vertebra), M48.51 — Collapsed vertebra, not elsewhere classified, occipito-atlanto-axial region (vertebra, occipito-atlanto-axial region), M48.52 — Collapsed vertebra, not elsewhere classified, cervical region (vertebra, cervical region), M48.53 — Collapsed vertebra, not elsewhere classified, cervicothoracic region (vertebra, cervicothoracic region), M48.54 — Collapsed vertebra, not elsewhere classified, thoracic region (vertebra, thoracic region), M48.55 — Collapsed vertebra, not elsewhere classified, thoracolumbar region (vertebra, thoracolumbar region), M48.56 — Collapsed vertebra, not elsewhere classified, lumbar region (vertebra, lumbar region), M48.57 — Collapsed vertebra, not elsewhere classified, lumbosacral region (vertebra, lumbosacral region), M48.58 — Collapsed vertebra, not elsewhere classified, sacral and sacrococcygeal region (vertebra, sacrococcygeal region), M80.88 — Other osteoporosis with current pathological fracture, vertebra(e) (vertebra, in, osteoporosis), M95.0 — Acquired deformity of nose (nose), O08.3 — Shock following ectopic and molar pregnancy (vascular, following ectopic or molar pregnancy), O29.02 — Pressure collapse of lung due to anesthesia during pregnancy (lung, pressure due to anesthesiaor other sedation, in pregnancy), O74.1 — Other pulmonary complications of anesthesia during labor and delivery (lung, pressure due to anesthesiaor other sedation, during labor and delivery), O75.1 — Shock during or following labor and delivery (during or, after labor and delivery), O89.09 — Other pulmonary complications of anesthesia during the puerperium (lung, pressure due to anesthesiaor other sedation, postpartum, puerperal), P29.89 — Other cardiovascular disorders originating in the perinatal period (vascular, newborn), Q16.5 — Congenital malformation of inner ear (labyrinth, membranous), R55 — Syncope and collapse, R57.0 — Cardiogenic shock (cardiovascular), +18 more

Contextual Map

Every relationship of M84.58XK in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run M84.58XK with this related code in Claim Check

Hierarchy

Referenced by Excludes1 notes

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 08 — Diseases and Disorders of the Musculoskeletal System and Connective Tissue[MDC crossing]: “Diseases and Disorders of the Musculoskeletal System and Connective Tissue — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 18,508 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Nearest codes (40)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Common coding questions

Does M84.58XK require a 7th character?

Yes. The appropriate 7th character is to be added to each code from subcategory M84.5:.

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Coding guidelines Official source data
ICD-10-CM Official Guidelines for Coding and Reporting (FY2026), quoted by section Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Pathological fracture in neoplastic disease, other specified site, subsequent encounter for fracture with nonunion

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to M84.58XK in its code family, with their registry titles.

View all codes in the M84 family