2027 ICD-10-CM Diagnosis Code M20.099Other deformity of finger(s), unspecified finger(s)

ICD-10-CM Codes›M00–M99›M20-M25›M20

ICD-10-CM M20.099
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

M20.099 is a billable ICD-10-CM diagnosis code for other deformity of finger(s), unspecified finger(s). It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 564 through 566. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Acquired deformities (excluding foot).

Code Identity

ICD-10-CM Code
M20.099
Billable Status
Yes — Valid for Submission
Code Describes
Other deformity of finger(s), unspecified finger(s)
Short Description
Other deformity of finger(s), unspecified finger(s)
Same as the full description in the CMS dataset.
Parent Code
M20.09
Other deformity of finger(s)

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM20-M25Other joint disorders
CategoryM20Acquired deformities of fingers and toes
This CodeM20.099Other deformity of finger(s), unspecified finger(s)

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abduction deformity of finger
  • Abnormal curvature of distal phalanx of hand
  • Abnormal curvature of distal phalanx of index finger
  • Abnormal curvature of distal phalanx of little finger
  • Abnormal curvature of distal phalanx of middle finger
  • Abnormal curvature of distal phalanx of ring finger
  • Abnormal curvature of distal phalanx of thumb
  • Abnormal curvature of middle phalanx of finger
  • Abnormal curvature of middle phalanx of index finger
  • Abnormal curvature of middle phalanx of little finger
  • Abnormal curvature of middle phalanx of middle finger
  • Abnormal curvature of middle phalanx of ring finger
  • Abnormal curvature of phalanx of hand
  • Abnormal curvature of phalanx of index finger
  • Abnormal curvature of phalanx of little finger
  • Abnormal curvature of phalanx of middle finger
  • Abnormal curvature of phalanx of ring finger
  • Abnormal curvature of phalanx of thumb
  • Abnormal curvature of proximal phalanx of index finger
  • Abnormal curvature of proximal phalanx of little finger
  • Abnormal curvature of proximal phalanx of middle finger
  • Abnormal curvature of proximal phalanx of ring finger
  • Abnormal curvature of proximal phalanx of thumb
  • Acquired deformity of the thumb
  • Acquired fixed flexion deformity of joint of upper limb
  • Acquired fixed flexion deformity of thumb
  • Adduction deformity of finger
  • Deviation of finger
  • Dropped finger
  • Extension deformity of finger
  • Fixed extension deformity of the thumb
  • Fixed flexion deformity of the thumb
  • Overriding fingers
  • Rotational deformity of finger
  • Rotational deformity of thumb
  • Short finger
  • Spindling of finger
  • Tapering fingers
  • Thumb joint deformity
  • Ulnar deviation of hand
  • Ulnar deviation of the thumb
  • Ulnar drift
  • Z deformity of thumb

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to M20.099: its own notes plus those printed at M20.0, M20, block M00-M25, block M20-M25, and Chapter 13. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Block M00-M25 applies to 2,249 codes
  • Disorders affecting predominantly peripheral (limb) joints

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From M20.0 Deformity of finger(s) applies to 15 codes
  • clubbing of fingers (R68.3)
  • palmar fascial fibromatosis [Dupuytren] (M72.0)
  • trigger finger (M65.3)
From M20 Acquired deformities of fingers and toes applies to 33 codes
  • acquired absence of fingers and toes (Z89.-)
  • congenital absence of fingers and toes (Q71.3-, Q72.3-)
  • congenital deformities and malformations of fingers and toes (Q66.-, Q68-Q70, Q74.-)

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 M20-M25 Other joint disorders applies to 719 codes
From Chapter 13 (M00-M99) Diseases of the musculoskeletal system and connective tissue applies to 6,687 codes
  • 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)

Notes

General instructions on how these codes are used.

From Chapter 13 (M00-M99) Diseases of the musculoskeletal system and connective tissue applies to 6,687 codes
  • Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name M20.099, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming M20.099: its condition is not part of those codes, and both may be reported when the patient has both.

  • M21 Other acquired deformities of limbs
    acquired deformities of fingers or toes (M20.-) names M20.-, which includes this code

Clinical ClassificationClinical

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

CCSR MUS023
Acquired deformities (excluding foot)
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Finger Injuries and Disorders

You use your fingers and thumbs to do everything from grasping objects to playing musical instruments to typing. When there is something wrong with them, it can make life difficult. Common problems include:

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert M20.099 to ICD-9-CMHistory

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

ICD-9-CM
736.29 Acq finger deformity NEC
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 M20.099Overview

What is the ICD-10 code for other deformity of finger(s), unspecified finger(s)?

The ICD-10-CM code for other deformity of finger(s), unspecified finger(s) is M20.099 (sometimes written as M20099). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is M20.099 (Other deformity of finger(s)) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other deformity of finger(s), unspecified finger(s) on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does M20.099 group to?

When other deformity of finger(s), unspecified finger(s) is the principal diagnosis on an inpatient stay, it groups to MS-DRG 564, 566, 565, with relative weights from 0.7374 to 1.4909 depending on complications. Higher weights mean higher Medicare reimbursement.

Can M20.099 be reported with R68.3?

Not as a rule. The Excludes1 note at M20.0, which applies to M20.099, lists "clubbing of fingers (R68.3)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What is the ICD-9 equivalent of M20.099?

Under the General Equivalence Mappings, other deformity of finger(s), unspecified finger(s) converts to ICD-9-CM 736.29 (acq finger deformity NEC). The mapping is approximate, so confirm the match fits the documentation.