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ICD-10-CM Z89.449: Acquired absence of unspecified ankle

Z89.449 is the billable ICD-10-CM code for acquired absence of unspecified ankle, in category Z89 (Acquired absence of limb) of the Persons with potential health hazards related to family and personal history and certain conditions influencing health status section. As a principal diagnosis it groups to MS-DRG 951 Other Factors Influencing Health Status (MDC 23 MDC 23: Factors Influencing Health Status and Other Contacts with Health Services). It maps to HCC 409 (Amputation Status, Lower Limb/Amputation Complications) in CMS-HCC V28.

Compiled from CMS files by the QuickIntell RCM Editorial Team · Data effective · Method: reference methodology · Report a data correction

Data currency: ICD-10-CM code descriptions: FY2027 (effective October 1, 2026); IPPS Table 5 (MS-DRG weights): v44 FY2027 (final rule + CN3) (effective October 1, 2026); ICD-10-CM to HCC mapping: PY2027 initial ICD-10-CM mappings (dates of service 2026) (payment year 2027); Medicare Coverage Database billing and coding articles: MCD release October 8, 2026 (effective October 4, 2026). Next CMS release: FY2028 code files, effective October 1, 2027 for the ICD-10-CM code descriptions; FY2028 final rule (August 2027), effective October 1, 2027; an April 1 interim grouper update when CMS issues one for the IPPS Table 5 (MS-DRG weights); PY2028 advance notice (February 2027) and the PY2027 midyear final mapping (spring 2027) for the ICD-10-CM to HCC mapping; weekly, every Thursday for the Medicare Coverage Database billing and coding articles.

Code
Z89.449
billable FY2027 ICD-10-CM code
Category
Z89 Acquired absence of limb
Chapter
21: Factors influencing health status and contact with health services (Z00-Z99)
CC/MCC (MS-DRG v44)
Neither
CMS-HCC V28
HCC 409
POA reporting
Exempt

Tabular list notes for Z89.449

The tabular list has no notes on Z89.449 itself; the notes below apply from its parent headings.

Inherited from Z89 (Acquired absence of limb)

Includes
  • amputation status
  • postprocedural loss of limb
  • post-traumatic loss of limb
Excludes1 (never coded together)
  • acquired deformities of limbs (M20-M21)
  • congenital absence of limbs (Q71-Q73)

Inherited from Z89.44 (Acquired absence of ankle)

Inclusion terms
  • Disarticulation of ankle

MS-DRG grouping when Z89.449 is the principal diagnosis

MS-DRG v44 groups for Z89.449 as principal diagnosis
MDCMS-DRGs
23 MDC 23: Factors Influencing Health Status and Other Contacts with Health Services951

The final group also depends on procedures, secondary diagnoses and discharge status; the MS-DRG lookup for Z89.449 shows the full grouping logic.

CC/MCC status and inpatient edits

Z89.449 is neither a CC nor an MCC under MS-DRG v44, so as a secondary diagnosis it does not raise the MS-DRG severity level. Check Z89.449 against a principal diagnosis.

  • Present on admission: exempt from POA indicator reporting (FY2027 exempt list).
  • Medicare Code Editor: unacceptable principal diagnosis.

CMS-HCC V28 risk adjustment

In the PY2027 mapping, Z89.449 maps to HCC 409 (Amputation Status, Lower Limb/Amputation Complications). The HCC lookup shows the RAF weight and the hierarchy.

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Frequently asked questions

What does ICD-10-CM Z89.449 mean?

Z89.449 means acquired absence of unspecified ankle. It is one of 25 billable codes under Z89, acquired absence of limb.

Which MS-DRG does Z89.449 group to?

As the principal diagnosis, Z89.449 groups to MS-DRG 951 Other Factors Influencing Health Status (MDC 23 MDC 23: Factors Influencing Health Status and Other Contacts with Health Services) under MS-DRG v44, before procedures and secondary diagnoses are applied.

Does Z89.449 map to an HCC?

Yes: HCC 409, Amputation Status, Lower Limb/Amputation Complications, in the PY2027 CMS-HCC V28 mapping.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.

Disclaimer

The descriptor and notes are reproduced from the FY2027 ICD-10-CM files; MS-DRG, CC/MCC and HCC facts come from the CMS FY2027 and PY2027 tables. Code from the medical record and the ICD-10-CM Official Guidelines. Not legal, clinical or billing advice.

Found a figure that does not match the CMS file? Report a data correction with the CMS file and the value you expected; the request reaches the editorial team through the contact form.