2027 ICD-10-CM Diagnosis Code S91.001DUnspecified open wound, right ankle, subsequent encounter

ICD-10-CM Codes›S00–T88›S90-S99›S91

ICD-10-CM S91.001D
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

S91.001D is a billable ICD-10-CM diagnosis code for unspecified open wound, right ankle, subsequent encounter. The 7th character D marks it as a subsequent encounter code, used during routine care in the healing or recovery phase. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 949 through 950. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Open wounds to limbs, subsequent encounter.

Code Identity

ICD-10-CM Code
S91.001D
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified open wound, right ankle, subsequent encounter
Short Description
Unspecified open wound, right ankle, subsequent encounter
Same as the full description in the CMS dataset.
Parent Code
S91.001
Unspecified open wound, right ankle

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS90-S99Injuries to the ankle and foot
CategoryS91Open wound of ankle, foot and toes
This CodeS91.001DUnspecified open wound, right ankle, subsequent encounter

Present on Admission (POA)Billing

S91.001D is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Injuries to the ankle and foot (S90-S99).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bimalleolar fracture of right ankle
  • Dislocation of joint of right ankle
  • Fracture of right lateral malleolus
  • Fracture of right medial malleolus
  • Open bimalleolar fracture
  • Open bimalleolar fracture of right ankle
  • Open dislocation of ankle
  • Open fracture of distal end of right fibula
  • Open fracture of distal right tibia
  • Open fracture of distal tibia and distal fibula
  • Open fracture of right ankle joint region
  • Open fracture of right fibula
  • Open fracture of right lateral malleolus of fibula
  • Open fracture of right medial malleolus
  • Open traumatic dislocation of joint of right ankle
  • Open trimalleolar fracture
  • Open trimalleolar fracture of right ankle
  • Open wound of right ankle
  • Trimalleolar fracture of right ankle

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Open wound of ankle, foot and toes (S91). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to S91.001D: its own notes plus those printed at S91, block S90-S99, and Chapter 19. 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.

From S91 Open wound of ankle, foot and toes applies to 360 codes
  • open fracture of ankle, foot and toes (S92.-with 7th character B)
  • traumatic amputation of ankle and foot (S98.-)

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.

From Block S90-S99 Injuries to the ankle and foot applies to 3,324 codes
  • burns and corrosions (T20-T32)
  • fracture of ankle and malleolus (S82.-)
  • frostbite (T33-T34)
  • insect bite or sting, venomous (T63.4)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

From S91 Open wound of ankle, foot and toes applies to 360 codes
  • any associated wound infection

Notes

General instructions on how these codes are used.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

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.

From S91 Open wound of ankle, foot and toes applies to 360 codes
  • The appropriate 7th character is to be added to each code from category S91
Values for category S91 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter
  • Dsubsequent encounter this code
  • 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 S91.001D, its category, or a range that includes it.

Excludes2 2

These codes carry an Excludes2 note naming S91.001D: its condition is not part of those codes, and both may be reported when the patient has both.

  • S71 Open wound of hip and thigh
    open wound of ankle, foot and toes (S91.-) names S91.-, which includes this code
  • S81 Open wound of knee and lower leg
    open wound of ankle and foot (S91.-) names S91.-, which includes this code

Code Also 3

These codes say S91.001D may also be needed to fully describe the condition. The note gives no sequencing direction.

  • S94 Injury of nerves at ankle and foot level
    any associated open wound (S91.-) names S91.-, which includes this code
  • S95 Injury of blood vessels at ankle and foot level
    any associated open wound (S91.-) names S91.-, which includes this code
  • S96 Injury of muscle and tendon at ankle and foot level
    any associated open wound (S91.-) names S91.-, which includes this code

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ049
Open wounds to limbs, subsequent encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

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 S91.001D to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
V58.89 Other specfied aftercare
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About S91.001DOverview

What is the ICD-10 code for unspecified open wound, right ankle, subsequent encounter?

The ICD-10-CM code for unspecified open wound, right ankle, subsequent encounter is S91.001D (sometimes written as S91001D). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is S91.001D (Unspecified open wound, right ankle) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified open wound, right ankle, subsequent encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character D in S91.001D mean?

The final character D marks a subsequent encounter: use it for routine care while the unspecified open wound, right ankle is healing, after active treatment has ended.

What MS-DRG does S91.001D group to?

When unspecified open wound, right ankle, subsequent encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 950, 949, with relative weights from 0.7661 to 1.1231 depending on complications. Higher weights mean higher Medicare reimbursement.

Is S91.001D exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for unspecified open wound, right ankle, subsequent encounter on inpatient claims. The code appears in the Injuries to the ankle and foot (S90-S99) range of the CMS exempt list.