2026 ICD-10-CM Diagnosis Code M06.00

Approximate Synonyms

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

Clinical Classification

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

MS-DRG Mapping for ICD-10-CM Code M06.00

Diagnosis-Related Groups (DRGs) are used to classify hospital cases for billing and healthcare management. They help standardize how hospitals and other providers are reimbursed for inpatient care. Patients are grouped based on their principal diagnosis into broader categories called Major Diagnostic Categories (MDCs).

Once assigned to a DRG, the hospital receives a set payment for the patient’s care, regardless of the actual services provided. This fixed rate is intended to cover the typical cost of treating patients within that group. The payment amount depends on the DRG's relative weight, which reflects the expected complexity and cost of care based on the severity of the patient’s condition.

Diagnostic related groups encourage healthcare providers to focus on quality and efficiency in patient care while managing costs effectively. The diagnosis code is present in the following groups for version MS-DRG V43.0 applicable from 10/01/2025 through 09/30/2026.

Convert M06.00 to ICD-9-CM

Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.

Patient Education

Rheumatoid Arthritis

What is rheumatoid arthritis?

Rheumatoid arthritis (RA) is a form of arthritis that causes pain, swelling, and stiffness in your joints. RA is an autoimmune disease. Although it is most common in the wrist and fingers, this disease can cause your immune system to attack any joint tissue. The inflammation (swelling) that comes with RA can also affect other body parts. Inflammation could cause medical issues in your eyes, skin, heart, nerves, blood, or lungs.

RA differs from osteoarthritis, a common arthritis that often comes with age. RA affects the lining of your joints and damages the tissue that covers the ends of the bones in a joint. Eventually, this might cause your joints to not work as well.

There is no cure for RA, but early treatment can help you manage symptoms, reduce joint damage, and lead a productive life.

Who is more likely to get rheumatoid arthritis?

Rheumatoid arthritis can happen at any age, but your risk increases as you become an older adult. Your chance of developing RA can also increase if:

• You're a woman. Women are more likely to get RA than men.
• You have a family history. If a member of your family has RA, you're more likely to get the disease.
• You're a smoker. Smoking over a long period of time increases your risk of getting RA and how serious the disease can be.
• You have other medical conditions that may increase your risk of getting RA. These include obesity, gum disease, and lung disease.

What causes rheumatoid arthritis?

No one knows what causes rheumatoid arthritis. A few things that might play a part in getting RA include:

• Your genes are parts of DNA in your cells that are passed down from your parents. Certain genes may increase your risk of getting rheumatoid arthritis, but not everyone with these genes gets RA.
• The environment, which includes things such as cigarette smoke, sometimes triggers RA symptoms.
• Hormones are chemical messengers in your bloodstream that control the actions of certain cells or organs. Researchers think that sex hormones might play a role in getting RA. Women are more likely to develop the disease, and RA symptoms may change during and after pregnancy.

What are the symptoms of rheumatoid arthritis?

Your immune system may start turning against your body's joints and tissues years before you notice any symptoms of RA. The changes from this type of immune malfunction usually settle in your joints.

RA affects people differently. You might have the disease for only a short time, or your symptoms might come and go. The severe form can be chronic (long-lasting) and may last a lifetime.

Symptoms of rheumatoid arthritis may include:

• Joint pain or stiffness when moving. This is usually worse in the morning or after inactivity. RA usually affects both joints. If one of your hands or knees is affected, so is the other.
• Joint tenderness, redness, and warmth.
• Joint swelling may make daily activities hard. These could include things such as combing your hair, buttoning your clothes, or bending your knees.
• Fatigue, fever, and a loss of appetite.
• Hard bumps (rheumatoid nodules) under your skin near the joints.

How is rheumatoid arthritis diagnosed?

There's no single test for rheumatoid arthritis. The disease develops over time. At first, you may only have a few symptoms, making it hard to diagnose RA in its early stages. To find out if you have RA, your health care provider may:

• Ask about your medical history, including your symptoms.
• Ask about your family health history, including relatives who have had RA.
• Do a physical exam, which includes checking your joints, looking for rashes or nodules, and listening to your chest for signs of inflammation in your lungs.
• Order blood tests or imaging studies (x-ray or ultrasound) to make sure other health conditions aren't causing your symptoms since they may be like other types of arthritis and joint conditions.

Your provider may refer you to a rheumatologist (a doctor who specializes in arthritis care) for tests, diagnosis, and care.

What are the treatments for rheumatoid arthritis?

There is no cure for RA, but early treatment can help prevent your symptoms from getting worse and damaging your joints. Treatment can include medicine, lifestyle changes, and surgery. These may slow or stop joint damage and reduce pain and swelling.

Your provider may use a combination of treatments. Your treatment may change based on your symptoms.

You can help manage your RA symptoms if you:

• Are physically active
• Keep a healthy weight
• Avoid injuries to your joints
• Avoid activities that have repetitive motions, like bending your knee over and over
• Stop smoking, or don't start

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases

[Learn More in MedlinePlus]

Rheumatoid arthritis

Rheumatoid arthritis is a disease that causes chronic inflammation that primarily affects the joints. The most common signs and symptoms are pain, swelling, and stiffness of the joints. This condition frequently affects the hands and feet, although the shoulders, hips, spine, and knees may become involved in the later stages of 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 may have trouble with tasks such as opening jars, turning doorknobs, or fastening buttons. Joint pain and stiffness tend to be worse after waking up in the morning or after a long rest. 

Rheumatoid arthritis can cause inflammation in other tissues and organs, including the eyes, skin, heart, and blood vessels. Affected individuals may also have inflammation in the lungs, which is known as interstitial lung disease. 

Additional signs and symptoms of rheumatoid arthritis 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.

Most people who have rheumatoid arthritis are 55 years old and older, although it can affect adults of any age. The signs and symptoms of rheumatoid arthritis usually appear in mid to late adulthood. Many affected people have recurrent episodes of symptoms (flares) followed by periods with no symptoms (remissions). 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.

[Learn More in MedlinePlus]

Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic (long-lasting) disease that mostly affects joints, such as the wrist, hands, feet, spine, knees, and jaw.
[Learn More in MedlinePlus]

Code History

• FY 2026 - No Change, effective from 10/1/2025 through 9/30/2026
• FY 2025 - No Change, effective from 10/1/2024 through 9/30/2025
• 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.