2027 ICD-10-CM Diagnosis Code H50.659Medial rectus muscle entrapment, unspecified eye

ICD-10-CM Codes›H00–H59›H49-H52›H50

ICD-10-CM H50.659
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

H50.659 is a billable ICD-10-CM diagnosis code for medial rectus muscle entrapment, unspecified eye. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 124 through 125. Coders also document this condition as entrapment of medial rectus muscle. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Strabismus.

Code Identity

ICD-10-CM Code
H50.659
Billable Status
Yes — Valid for Submission
Code Describes
Medial rectus muscle entrapment, unspecified eye
Short Description
Medial rectus muscle entrapment, unspecified eye
Same as the full description in the CMS dataset.
Parent Code
H50.65
Medial rectus muscle entrapment

Code Classification

ChapterH00–H59Diseases of the eye and adnexa
SectionH49-H52Disorders of ocular muscles, binocular movement, accommodation and refraction
CategoryH50Other strabismus
This CodeH50.659Medial rectus muscle entrapment, unspecified eye

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Entrapment of medial rectus muscle

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to H50.659: its own notes plus those printed at block H49-H52 and Chapter 7. A note printed at a category, block or chapter applies to every code under it.

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 H49-H52 Disorders of ocular muscles, binocular movement, accommodation and refraction applies to 150 codes
  • nystagmus and other irregular eye movements (H55)
From Chapter 7 (H00-H59) Diseases of the eye and adnexa applies to 2,677 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • diabetes mellitus related eye conditions (E09.3-, E10.3-, E11.3-, E13.3-)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury (trauma) of eye and orbit (S05.-)
  • 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)
  • syphilis related eye disorders (A50.01, A50.3-, A51.43, A52.71)

Notes

General instructions on how these codes are used.

From Chapter 7 (H00-H59) Diseases of the eye and adnexa applies to 2,677 codes
  • Use an external cause code following the code for the eye condition, if applicable, to identify the cause of the eye 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 H50.659, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming H50.659: its condition is not part of those codes, and both may be reported when the patient has both.

  • H53.03 Strabismic amblyopia
    strabismus (H50.-) names H50.-, which includes this code

Clinical ClassificationClinical

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

CCSR EYE007
Strabismus
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Eye Injuries

The structure of your face helps protect your eyes from injury. Still, injuries can damage your eye, sometimes severely enough that you could lose your vision. Most eye injuries are preventable. If you play sports or work in certain jobs, you may need protection.

Read the full article at MedlinePlus

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

Code History & ChangesHistory

Replacement H50.659 replaces the following previously assigned code(s):

  • H50.69 - Other mechanical strabismus
FY 2024AddedAdded to the ICD-10-CM code setEffective October 1, 2023.
FY 2025–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About H50.659Overview

What is the ICD-10 code for medial rectus muscle entrapment, unspecified eye?

The ICD-10-CM code for medial rectus muscle entrapment, unspecified eye is H50.659 (sometimes written as H50659). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is H50.659 (Medial rectus muscle entrapment) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report medial rectus muscle entrapment, unspecified eye on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does H50.659 group to?

When medial rectus muscle entrapment, unspecified eye is the principal diagnosis on an inpatient stay, it groups to MS-DRG 125, 124, with relative weights from 0.7699 to 1.2470 depending on complications. Higher weights mean higher Medicare reimbursement.