S56.312A - Strain of extensor or abductor muscles, fascia and tendons of left thumb at forearm level, initial encounter

Version 2023
ICD-10:S56.312A
Short Description:Strain extn/abdr musc/fasc/tend of l thm at forarm lv, init
Long Description:Strain of extensor or abductor muscles, fascia and tendons of left thumb at forearm level, initial encounter
Status: Valid for Submission
Version:ICD-10-CM 2023
Code Classification:
  • Injury, poisoning and certain other consequences of external causes (S00–T98)
    • Injuries to the elbow and forearm (S50-S59)
      • Injury of muscle, fascia and tendon at forearm level (S56)

S56.312A is a billable ICD-10 code used to specify a medical diagnosis of strain of extensor or abductor muscles, fascia and tendons of left thumb at forearm level, initial encounter. The code is valid during the fiscal year 2023 from October 01, 2022 through September 30, 2023 for the submission of HIPAA-covered transactions.

S56.312A is an initial encounter code, includes a 7th character and should be used while the patient is receiving active treatment for a condition like strain of extensor or abductor muscles fascia and tendons of left thumb at forearm level. According to ICD-10-CM Guidelines an "initial encounter" doesn't necessarily means "initial visit". The 7th character should be used when the patient is undergoing active treatment regardless if new or different providers saw the patient over the course of a treatment. The appropriate 7th character codes should also be used even if the patient delayed seeking treatment for a condition.

Coding Guidelines

The appropriate 7th character is to be added to each code from block Injury of muscle, fascia and tendon at forearm level (S56). Use the following options for the aplicable episode of care:

Convert to ICD-9 Code

Source ICD-10 CodeTarget ICD-9 Code
S56.312A841.9 - Sprain elbow/forearm NOS
Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

Patient Education


Arm Injuries and Disorders

Of the 206 bones in your body, three of them are in your arm: the humerus, radius, and ulna. Your arms are also made up of muscles, joints, tendons, and other connective tissue. Injuries to any of these parts of the arm can occur during sports, a fall, or an accident.

Types of arm injuries include :

You may also have problems or injure specific parts of your arm, such as your hand, wrist, elbow, or shoulder.


[Learn More in MedlinePlus]

Sprains and Strains

A sprain is a stretched or torn ligament. Ligaments are tissues that connect bones at a joint. Falling, twisting, or getting hit can all cause a sprain. Ankle and wrist sprains are common. Symptoms include pain, swelling, bruising, and being unable to move your joint. You might feel a pop or tear when the injury happens.

A strain is a stretched or torn muscle or tendon. Tendons are tissues that connect muscle to bone. Twisting or pulling these tissues can cause a strain. Strains can happen suddenly or develop over time. Back and hamstring muscle strains are common. Many people get strains playing sports. Symptoms include pain, muscle spasms, swelling, and trouble moving the muscle.

At first, treatment of both sprains and strains usually involves resting the injured area, icing it, wearing a bandage or device that compresses the area, and medicines. Later treatment might include exercise and physical therapy.

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases


[Learn More in MedlinePlus]

Code History