Z91.81: History of falling

The ICD-10-CM code for a history of falling or a documented risk for falling, when the patient has fallen in the past and is at risk for future falls.

Billable

FY2027

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At a glance

Code Family

Z91.8: Other specified personal risk factors, not elsewhere classified.

DRG Grouping

MS-DRG 951, Other factors influencing health status, when Z91.81 is the principal diagnosis under the FY2027 MS-DRG v44 grouper.

HCC Mapping (v28)

None. Z91.81 does not appear in the CMS-HCC v28 diagnosis crosswalk.

Family Specificity

Nine billable codes sit in Z91.8, including Z91.81.

Billable

Yes. Z91.81 is a complete code in the FY2027 billable code list.

Effective Date

Valid in the FY2026 code set and unchanged in the FY2027 update.

Which Z91.8 code do I assign?

Z91.81 is the only fall code in subcategory Z91.8, whose other codes cover unrelated personal risk factors. The choice that matters is between Z91.81, R29.6 for a recent fall under investigation, and the injury and external cause codes for a fall that caused harm at this encounter.

When documentation says…

Code

History of falls, at risk for future falls

Z91.81

History of falling. The Index sends History, personal, fall, falling to this code. The note should record the prior fall or falls and the provider's statement that the patient remains at risk.

Fall risk or at risk for falls

Z91.81

At risk for falling is the inclusion term at Z91.81. The Index sends At risk, for, falling and Problem (with) (related to), falling here. The main term Risk has no fall subterm.

Recent fall, cause being worked up

R29.6

Repeated falls. Guideline I.C.18.d states that R29.6 is for use when a patient has recently fallen and the reason for the fall is being investigated. R29.6 and Z91.81 may be assigned together when appropriate.

Tendency to fall or falling gait

R29.6

The Index sends Tendency, to fall, Gait abnormality, falling and Falling, falls (repeated) to R29.6, not to Z91.81. The note should describe the falls or the tendency the provider observed.

Fell today and fractured the right femoral neck

S72.001A

Fracture of unspecified part of neck of right femur, initial encounter for closed fracture. The injury is coded first. The Chapter 19 note calls for secondary Chapter 20 codes to show the cause of injury.

Fall at this encounter, mechanism not described

W19.XXXA

Unspecified fall, initial encounter. The External Cause Index sends Fall, falling (accidental) to W19. It follows the injury code and is never the first-listed or principal diagnosis (Section I.C.20.a.6).

Healed hip fracture from a past fall

Z87.81

Personal history of (healed) traumatic fracture. Category Z91 carries an Excludes2 note for personal history of physical injury and trauma. Z87.81 and Z91.81 may both be reported when the provider documents both.

Tabular notes

EXCLUDES1

Z91.81 carries no Excludes1 note. None sits above it at Z91.8, Z91, the Z77-Z99 block or Chapter 21.

R26.2, difficulty in walking, carries an Excludes1 note for falling (R29.6). It does not name Z91.81.

EXCLUDES2

Category Z91 carries an Excludes2 note for contact with and (suspected) exposures hazardous to health (the Z77 codes), exposure to pollution and other problems related to physical environment (the Z77.1 codes), female genital mutilation status (the N90.81 codes), occupational exposure to risk factors (the Z57 codes) and personal history of physical injury and trauma (Z87.81 and the Z87.82 codes). The patient may have both conditions.

R29.6 carries an Excludes2 note for at risk for falling (Z91.81) and history of falling (Z91.81). Guideline I.C.18.d allows R29.6 and Z91.81 together when appropriate.

The W00-W19 falls block carries an Excludes2 note for at risk for fall (history of fall) Z91.81. A W00-W19 external cause code and Z91.81 may both be reported.

CODE ALSO

The Z77-Z99 block carries a Code also note for any follow-up examination (Z08-Z09). It applies to Z91.81 as a code in that block.

USE ADDITIONAL

Z91.81 carries no use additional code or code first instruction. None sits above it at Z91.8, Z91, the Z77-Z99 block or Chapter 21.

FY2027: EFFECTIVE 1 OCTOBER 2026

The FY2027 codes addenda make no addition, deletion or revision of a code in subcategory Z91.8. Z91.81 is in the FY2027 billable code list.

The FY2027 tabular addenda leave Z91.8, R29.6 and the W00-W19 block unchanged. Their only change in category Z91 adds Alpha-gal syndrome (AGS) as an inclusion term at Z91.014.

Operational & financial impact

Why specificity matters beyond the chart: risk adjustment, DRG assignment and denial exposure all follow from which code is selected.

CMS-HCC v28 (PY2024+)

No code in subcategory Z91.8 appears in the CMS-HCC v28 diagnosis crosswalk. R29.6, W19.XXXA and Z87.81 are absent from it too.

In the same crosswalk, some injuries from a current fall map to a payment HCC. S72.001A maps to HCC 402: Hip Fracture/Dislocation. S06.9X0A maps to HCC 399: Major Head Injury without Loss of Consciousness.

MS-DRG v44 (FY2027)

MS-DRG 951: Other factors influencing health status.

Z91.81 as principal diagnosis falls in MDC 23, Factors Influencing Health Status and Other Contacts with Health Services, and groups to this single DRG. The source is the CMS MS-DRG v44.0 Definitions Manual, Appendix B.

MS-DRG 951 has no with MCC or with CC split.

R29.6 as principal diagnosis groups to MS-DRG 091, 092 or 093, Other disorders of nervous system, in MDC 01.

WHERE SPECIFICITY IS LOST

Z91.81 does not describe an injury. A fall that caused harm at this encounter is coded with the injury code first, followed by the Chapter 20 codes for the fall.

Reporting Z91.81 for a recent fall whose cause is under investigation, without R29.6, departs from Guideline I.C.18.d.

Reporting W19.XXXA or any other Chapter 20 code as the first-listed or principal diagnosis conflicts with Section I.C.20.a.6.

External cause reporting is not nationally required. It applies when a state mandate or a payer requires it, per the Chapter 20 guidelines (Section I.C.20).

SEVERITY DESIGNATION (MS-DRG V44, FY2027)

Z91.81 is on neither list. It carries no CC or MCC designation as a secondary diagnosis.

No code in subcategory Z91.8 carries a CC or MCC designation.

Per Table 6I (Complete MCC List) and Table 6J (Complete CC List) of the FY2027 IPPS final rule (CMS-1849-F), MS-DRG v44.

Documentation checklist to support Z91.81

Chart elements that support code selection and reduce specificity-driven denials.

The prior fall or falls in the provider's own words, with approximate dates and any injury that resulted.

The provider's statement that the patient remains at risk for future falls, or the result of a documented fall risk assessment.

Whether a recent fall is still under investigation, which supports R29.6 with or without Z91.81 (Guideline I.C.18.d).

For a fall at this encounter, the injury, its site, its laterality and whether this is the initial or a subsequent encounter for the seventh character.

How the fall happened, where and during what activity, for the W00-W19 codes and the Y92 and Y93 codes where external cause reporting is required.

Any healed fracture from a past fall, which supports Z87.81 alongside Z91.81 under the Z91 Excludes2 note.

Findings documented with the falls, such as unsteadiness on feet (R26.81), difficulty walking (R26.2) or dizziness (R42), each coded on its own when the provider records it.

For an outpatient visit for another reason, the history of falls still recorded on the note, because history codes are acceptable on any medical record regardless of the reason for visit (Section I.C.21.c.4).

FAQ

Is Z91.81 a billable code?

Yes. Z91.81 is a complete code with no further characters. It appears in the FY2027 billable code list. Its parent Z91.8 is a subcategory header and cannot be reported.

What is the ICD-10 code for fall risk or at risk for falls?

Z91.81. At risk for falling is the inclusion term at Z91.81. The Alphabetic Index sends At risk, for, falling to it. The main term Risk has no fall subterm. Guideline I.C.18.d describes Z91.81 for a patient who has fallen in the past and is at risk for future falls.

What is the difference between Z91.81 and R29.6?

Guideline I.C.18.d gives each code its own use. R29.6 is for use when a patient has recently fallen and the reason for the fall is being investigated. Z91.81 is for use when a patient has fallen in the past and is at risk for future falls. The guideline allows both codes together when appropriate. The R29.6 Excludes2 note for Z91.81 permits the pairing.

Does Z91.81 map to an HCC under CMS-HCC v28?

No. Z91.81 does not appear in the CMS-HCC v28 diagnosis crosswalk. R29.6 and W19.XXXA do not appear in it either. Some injuries from a fall do map, such as S72.001A to HCC 402, Hip Fracture/Dislocation.

How do I code status post fall or a fall with injury?

The Alphabetic Index has no entry for status post fall. When a fall at this encounter caused an injury, code the injury first. The Chapter 19 note calls for secondary Chapter 20 codes for the cause, such as W19.XXXA for an unspecified fall at the initial encounter. Add Z91.81 when the provider also documents past falls and ongoing risk.

Can Z91.81 be the first-listed or principal diagnosis?

Yes, depending on the circumstances of the encounter. Section I.C.21.a allows a Z code as first-listed or secondary. Z91.81 is not on the first-listed-only list in Section I.C.21.c.15. When the encounter has another reason, such as screening or counseling, Section I.C.21.c.4 sequences that reason first and the history code as an additional diagnosis. As inpatient principal diagnosis, Z91.81 groups to MS-DRG 951 under the FY2027 MS-DRG v44 grouper.

What should the note document to support Z91.81?

The prior fall or falls and the provider's statement that the patient remains at risk for future falls. Record any injury from a past fall and any finding seen with the falls, such as unsteadiness or dizziness. Each of those findings takes its own code when the provider documents it.

What changed for Z91.81 in FY2027?

Nothing. The FY2027 codes and tabular addenda, effective 1 October 2026, make no change to Z91.81, subcategory Z91.8 or R29.6. The nearby gait category did change: the R26.2 Excludes1 note for unsteadiness on feet (R26.81) became an Excludes2 note.

Related codes

Codes in the same family as Z91.81. Only codes with a published page render as links.

Sibling codes in the Z91.8 family

Z91.82: Personal history of military deployment.
Z91.83: Wandering in diseases classified elsewhere, coded after the underlying disorder, such as Alzheimer's disease, autism or intellectual disabilities.
Z91.841: Risk for dental caries, low.
Z91.842: Risk for dental caries, moderate.
Z91.843: Risk for dental caries, high.
Z91.849: Unspecified risk for dental caries.
Z91.85: Personal history of military service.
Z91.89: Other specified personal risk factors, not elsewhere classified, when the provider documents a risk the Index sends there, such as at risk for social isolation.

Additional codes to consider

Codes outside the Z91.8 family considered alongside Z91.81.

Companion: code alongside when documented

R29.6: Repeated falls, when a recent fall is being investigated, which Guideline I.C.18.d allows with Z91.81.
Z87.81: Personal history of (healed) traumatic fracture, when a past fall caused a fracture that has healed.
W19.XXXA: Unspecified fall, initial encounter, after the injury code when a fall at this encounter caused an injury and the mechanism is not described.

Consider instead

S72.001A: Fracture of unspecified part of neck of right femur, initial encounter for closed fracture, coded first when a current fall fractured the right femoral neck.
S06.0X0A: Concussion without loss of consciousness, initial encounter, coded first when a current fall caused a concussion.
R26.81: Unsteadiness on feet, when the provider documents unsteadiness without a fall.
Z74.09: Other reduced mobility, when reduced mobility is documented without a fall.

Sources

All claims on this page derive from government and professional-standards sources.

National Center for Health Statistics. (2026). International classification of diseases, tenth revision, clinical modification (ICD-10-CM) FY2027 files. https://www.cdc.gov/nchs/icd/icd-10-cm/files.html
Centers for Medicare & Medicaid Services and National Center for Health Statistics. (2026). ICD-10-CM official guidelines for coding and reporting FY2027. https://ftp.cdc.gov/pub/Health_Statistics/NCHS/Publications/ICD10CM/2027/ICD-10-CM-October-1-2026-FY27-Guidelines.pdf
Centers for Medicare & Medicaid Services. (2025). 2026 model software/ICD-10 mappings. https://www.cms.gov/medicare/payment/medicare-advantage-rates-statistics/risk-adjustment/2026-model-software-icd-10-mappings
Centers for Medicare & Medicaid Services. (2026). MS-DRG classifications and software, version 44. https://www.cms.gov/medicare/payment/prospective-payment-systems/acute-inpatient-pps/ms-drg-classifications-and-software