ICD-10-CM Code M66.86

Spontaneous rupture of other tendons, lower leg

Version 2020 Non-Billable Code

Not Valid for Submission

M66.86 is a "header" nonspecific and non-billable code code, consider using a code with a higher level of specificity for a diagnosis of spontaneous rupture of other tendons, lower leg. The code is NOT valid for the year 2020 for the submission of HIPAA-covered transactions.

ICD-10:M66.86
Short Description:Spontaneous rupture of other tendons, lower leg
Long Description:Spontaneous rupture of other tendons, lower leg

Consider the following ICD-10 codes with a higher level of specificity:

  • M66.861 - Spontaneous rupture of other tendons, right lower leg
  • M66.862 - Spontaneous rupture of other tendons, left lower leg
  • M66.869 - Spontaneous rupture of other tendons, unspecified lower leg

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code M66.86 are found in the index:


Code Classification

  • Diseases of the musculoskeletal system and connective tissue (M00–M99)
    • Disorders of synovium and tendon (M65-M67)
      • Spontaneous rupture of synovium and tendon (M66)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020

Information for Patients


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.

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.


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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


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