Alphabetic Index FY2027

S53.121S

Posterior subluxation of right ulnohumeral joint, sequela

FY2027Chapter 19: Injury, poisoning and certain other consequences of external causes/S50–S59 Injuries to the elbow and forearm

BillableComplete code, valid to report
Care settingsHome Health Primary · Musculoskeletal Rehabilitation

S53.121S (also written S53121S) is a billable ICD-10-CM diagnosis code for posterior subluxation of right ulnohumeral joint, sequela. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 261 codes in category S53 (Dislocation and sprain of joints and ligaments of elbow). Its 7th character, S, means sequela. Its coding notes include a Use additional code instruction, a Code also instruction, 1 Excludes1 entry and 7 Excludes2 entries.

7th character

Category S53 requires a 7th character.

Assembled code S53.121S Open code

Guidelines tips

From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.

The 7th character depends on whether the patient is in active treatment, not on who sees the patient. An aftercare Z code is not used for injury aftercare.

Guidelines I.C.19.aInjuries: application of 7th charactersRead the official text

Each injury gets its own code unless a combination code exists, with the most serious injury first. Superficial injuries at the same site as a more severe injury are not coded. Injuries during medical care are coded as complications.

Guidelines I.C.19.bCoding of injuriesRead the official text

Use additional code

Add the listed code as a secondary code, if known.

Also from chapter/block level (1 note)
Inherited from Chapter 19 Injury, poisoning and certain other consequences of external causes
  • code to identify any retained foreign body, if applicable (Z18.-)

Code also

Two codes may be needed to describe the condition. This note gives no sequencing order.

Inherited from S53 Dislocation and sprain of joints and ligaments of elbow
  • any associated open wound

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from S53.1 Subluxation and dislocation of ulnohumeral joint
  • dislocation of radial head alone (S53.0-)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Inherited from S53 Dislocation and sprain of joints and ligaments of elbow
  • strain of muscle, fascia and tendon at forearm level (S56.-)
Also from chapter/block level (6 notes)
Inherited from S50–S59 Injuries to the elbow and forearm
Inherited from Chapter 19 Injury, poisoning and certain other consequences of external causes
  • birth trauma (P10-P15)
  • obstetric trauma (O70-O71)

Care settings

How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.

Home Health Primary

Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the Musculoskeletal Rehabilitation clinical group.

Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026

Includes

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

Inherited from S53 Dislocation and sprain of joints and ligaments of elbow
  • avulsion of joint or ligament of elbow
  • laceration of cartilage, joint or ligament of elbow
  • sprain of cartilage, joint or ligament of elbow
  • traumatic hemarthrosis of joint or ligament of elbow
  • traumatic rupture of joint or ligament of elbow
  • traumatic subluxation of joint or ligament of elbow
  • traumatic tear of joint or ligament of elbow

Notes

Also from chapter/block level (2 notes)
Inherited from Chapter 19 Injury, poisoning and certain other consequences of external causes
  • 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.