M05.40 - Rheumatoid myopathy with rheumatoid arthritis of unspecified site

Version 2023
ICD-10:M05.40
Short Description:Rheumatoid myopathy with rheumatoid arthritis of unsp site
Long Description:Rheumatoid myopathy with rheumatoid arthritis of unspecified site
Status: Valid for Submission
Version:ICD-10-CM 2023
Code Classification:
  • Diseases of the musculoskeletal system and connective tissue (M00–M99)
    • Inflammatory polyarthropathies (M05-M14)
      • Rheumatoid arthritis with rheumatoid factor (M05)

M05.40 is a billable ICD-10 code used to specify a medical diagnosis of rheumatoid myopathy with rheumatoid arthritis of unspecified site. The code is valid during the fiscal year 2023 from October 01, 2022 through September 30, 2023 for the submission of HIPAA-covered transactions.

Unspecified diagnosis codes like M05.40 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.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

Index to Diseases and Injuries References

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 this diagnosis code are found in the injuries and diseases index:

Code Edits

The Medicare Code Editor (MCE) detects and reports errors in the coding of claims data. The following ICD-10 Code Edits are applicable to this code:

Convert to ICD-9 Code

Source ICD-10 CodeTarget ICD-9 Code
M05.40714.0 - Rheumatoid arthritis
Combination Flag - Multiple codes are needed to describe the source diagnosis code. Correct coding should be done based on contextual judgment.
M05.40359.6 - Infl myopathy in oth dis
Combination Flag - Multiple codes are needed to describe the source diagnosis code. Correct coding should be done based on contextual judgment.

Patient Education


Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a form of arthritis that causes pain, swelling, stiffness and loss of function in your joints. It can affect any joint but is common in the wrist and fingers.

More women than men get rheumatoid arthritis. It often starts in middle age and is most common in older people. You might have the disease for only a short time, or symptoms might come and go. The severe form can last a lifetime.

Rheumatoid arthritis is different from osteoarthritis, the common arthritis that often comes with older age. RA can affect body parts besides joints, such as your eyes, mouth and lungs. RA is an autoimmune disease, which means the arthritis results from your immune system attacking your body's own tissues.

No one knows what causes rheumatoid arthritis. Genes, environment, and hormones might contribute. Treatments include medicine, lifestyle changes, and surgery. These can slow or stop joint damage and reduce pain and swelling.

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases


[Learn More in MedlinePlus]

Rheumatoid arthritis

Rheumatoid arthritis is a disease that causes chronic abnormal inflammation, primarily affecting the joints. The most common signs and symptoms are pain, swelling, and stiffness of the joints. Small joints in the hands and feet are involved most often, although larger joints (such as the shoulders, hips, and knees) may become involved later in the disease. Joints are typically affected in a symmetrical pattern; for example, if joints in the hand are affected, both hands tend to be involved. People with rheumatoid arthritis often report that their joint pain and stiffness is worse when getting out of bed in the morning or after a long rest.

Rheumatoid arthritis can also cause inflammation of other tissues and organs, including the eyes, lungs, and blood vessels. Additional signs and symptoms of the condition can include a loss of energy, a low fever, weight loss, and a shortage of red blood cells (anemia). Some affected individuals develop rheumatoid nodules, which are firm lumps of noncancerous tissue that can grow under the skin and elsewhere in the body.

The signs and symptoms of rheumatoid arthritis usually appear in mid- to late adulthood. Many affected people have episodes of symptoms (flares) followed by periods with no symptoms (remissions) for the rest of their lives. In severe cases, affected individuals have continuous health problems related to the disease for many years. The abnormal inflammation can lead to severe joint damage, which limits movement and can cause significant disability.


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Code History