2024 ICD-10-CM Diagnosis Code S86.91

Strain of unspecified muscle and tendon at lower leg level

ICD-10-CM Code:
S86.91
ICD-10 Code for:
Strain of unspecified muscle and tendon at lower leg level
Is Billable?
Not Valid for Submission
Code Navigator:

Code Classification

  • Injury, poisoning and certain other consequences of external causes
    (S00–T88)
    • Injuries to the knee and lower leg
      (S80-S89)
      • Injury of muscle, fascia and tendon at lower leg level
        (S86)

S86.91 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of strain of unspecified muscle and tendon at lower leg level. The code is not specific and is NOT valid for the year 2024 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Unspecified diagnosis codes like S86.91 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Specific Coding Applicable to Strain of unspecified muscle and tendon at lower leg level

Non-specific codes like S86.91 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for strain of unspecified muscle and tendon at lower leg level:

  • S86.911 for Strain of unspecified muscle(s) and tendon(s) at lower leg level, right leg - NON-BILLABLE CODE

  • Use S86.911A for initial encounter - BILLABLE CODE

  • Use S86.911D for subsequent encounter - BILLABLE CODE

  • Use S86.911S for sequela - BILLABLE CODE

  • S86.912 for Strain of unspecified muscle(s) and tendon(s) at lower leg level, left leg - NON-BILLABLE CODE

  • Use S86.912A for initial encounter - BILLABLE CODE

  • Use S86.912D for subsequent encounter - BILLABLE CODE

  • Use S86.912S for sequela - BILLABLE CODE

  • S86.919 for Strain of unspecified muscle(s) and tendon(s) at lower leg level, unspecified leg - NON-BILLABLE CODE

  • Use S86.919A for initial encounter - BILLABLE CODE

  • Use S86.919D for subsequent encounter - BILLABLE CODE

  • Use S86.919S for sequela - BILLABLE CODE

Coding Guidelines

The appropriate 7th character is to be added to each code from block Injury of muscle, fascia and tendon at lower leg level (S86). Use the following options for the aplicable episode of care:

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

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Patient Education


Leg Injuries and Disorders

Your legs are made up of bones, blood vessels, muscles, and other connective tissue. They are important for motion and standing. Playing sports, running, falling, or having an accident can damage your legs. Common leg injuries include sprains and strains, joint dislocations, and fractures (broken bones).

These injuries can affect the entire leg, or just the foot, ankle, knee, or hip. Certain diseases also lead to leg problems. For example, knee osteoarthritis, common in older people, can cause pain and limited motion. Problems in your veins in your legs can lead to varicose veins or deep vein thrombosis.


[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

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.