ICD 10 Coding Alert

Specify unspecified tenosynovitis diagnoses.

On Oct. 1, 2024, the Centers for Medicare & Medicaid Services (CMS) will update the ICD-10-CM code set with more than 250 new diagnosis codes that affect almost every category. Radiology coders will need to be aware of the multiple diagnosis code changes that you will encounter — from spinal conditions to medical oncology diagnoses.

Learn which changes are in store for radiology coders in FY 2025.

Identify Intervertebral Disc Degeneration With Pain Dx Codes

Healthcare providers who diagnose patients with intervertebral disc degeneration starting Oct. 1, 2024, will have more options for detailing any additional pain the patient is experiencing. If the physician diagnoses the patient with discogenic back pain, lower extremity pain, a combination of the two, or disc degeneration without mention of pain, you’ll assign one of the following codes for the lumbar region, coded under M51.36- (Other intervertebral disc degeneration, lumbar region):

• M51.360 (Other intervertebral disc degeneration, lumbar region with discogenic back pain only)
• M51.361 (Other intervertebral disc degeneration, lumbar region with lower extremity pain only)
• M51.362 (Other intervertebral disc degeneration, lumbar region with discogenic back pain and lower extremity pain)
• M51.369 (Other intervertebral disc degeneration, lumbar region without mention of lumbar back pain or lower extremity pain)

Simultaneously, if the disc degeneration occurs in the lumbosacral region, you’ll use one of the applicable codes under M51.37- (Other intervertebral disc degeneration, lumbosacral region):

• M51.370 (Other interver­tebral disc degeneration, lumbosacral region with discogenic back pain only)
• M51.371 (Other interver­tebral disc degeneration, lumbosacral region with lower extremity pain only)
• M51.372 (Other interver­tebral disc degeneration, lumbosacral region with discogenic back pain and lower extremity pain)
• M51.379 (Other intervertebral disc degeneration, lumbosacral region without mention of lumbar back pain or lower extremity pain)

“Degeneration is a condition where the disc is damaged. Sometimes the providers talk about it as spondylosis or arthritis, we hear those terms quite a bit. It’s damage of some sort,” said Deni Adams, CPC, CPB, CPPM, CEMC, CPEDC, of Kaleidoscope Health Systems in her AAPC webinar, “The Backbone of Spine Coding.”

The expansion of M51.36- and M51.37- will now also allow you to report pain types occurring alongside the disc degeneration with greater specificity. For example, you’ll assign add 6th character “0” if the diagnosis includes discogenic back pain only, you’ll use 6th character “1” if the diagnosis includes only lower extremity pain, but you’ll assign 6th character “2” for discogenic back pain and lower extremity pain.

“Discogenic back pain is pain typically caused by mechanically or chemically damaged discs, which can be due to aging or trauma,” says Kristen R. Taylor, CPC, CHC, CHIAP, associate partner at Pinnacle Enterprise Risk Consulting Services.

Understand New Unspecified Tenosynovitis Dx Codes

The 2025 ICD-10-CM code set adds several codes for tenosynovitis and synovitis diagnoses. Tenosynovitis is inflammation of the synovial membrane (protective sheath) that encloses the tendons. Providers may order imaging tests, such as X-rays, magnetic resonance imaging (MRI) or computed tomography (CT) scans, after a physical examination to get a complete picture of the patient’s tendons and the surrounding structures.

Starting October 1, M65.9- (Synovitis and tenosynovitis, unspecified) is converted to a parent code, and the codes within the new subcategory will provide greater detail regarding the location of the documented diagnosis of unspecified synovitis and tenosynovitis. You’ll assign M65.90 (Unspecified synovitis and tenosynovitis, unspecified site) when the provider’s report lists the condition without specificity of the type and identifying the affected body structure.

However, if the radiologist documents their impression of unspecified synovitis or tenosynovitis in upper or lower extremities or joints, you’ll look for an applicable code from one of the new code subcategories:

• M65.91- (Unspecified synovitis and tenosynovitis, shoulder)
• M65.92- (Unspecified synovitis and tenosynovitis, upper arm)
• M65.93- (Unspecified synovitis and tenosynovitis, forearm)
• M65.94- (Unspecified synovitis and tenosynovitis, hand)
• M65.95- (Unspecified synovitis and tenosynovitis, thigh)
• M65.96- (Unspecified synovitis and tenosynovitis, lower leg)
• M65.97- (Unspecified synovitis and tenosynovitis, ankle and foot)

You’ll also want to note that each of the above subcategories require 6th characters to complete the codes. The 6th characters identify the laterality, so you’ll use 1 for the right side, 2 for the left side, and 9 if the provider doesn’t specify the laterality.

Additionally, you will assign M65.98 (Unspecified synovitis and tenosynovitis, other site) when the provider does not specify the synovitis or tenosynovitis occurring in a body location that is different from what’s listed in M65.91- to M65.97-. If the provider documents the unspecified condition occurring in more than one location, you’ll assign M65.99 (Unspecified synovitis and tenosynovitis, multiple sites).

Take Note of These Hodgkin and Follicular Lymphoma in Remission Additions

ICD-10-CM 2025 has expanded C81.- (Hodgkin lymphoma) to include codes that indicate the patient’s condition is in remission for each subcategory in the group. The new codes follow the same first four characters as the existing Hodgkin lymphoma condition subcategories, but add a fifth character, “A,” to describe the patient’s remission status.

So, you will now code a patient in remission for lymphocyte-depleted Hodgkin lymphoma with C81.3A, while you’ll code a patient with lymphocyte-rich Hodgkin lymphoma that is now in remission with C81.4A.

You’ll see the same revision to the C82.- (Follicular lymphoma) codes. For example, a patient in remission for grade IIIa follicular lymphoma will be coded to C82.3A, while you will use C82.5A for a patient in remission for diffuse follicle center lymphoma.

Check Out These New Remission Status Codes for Other Lymphomas

ICD-10-CM 2025 has also expanded many of the lymphoma code groups to include “in remission” codes for some, but not all, code subcategories. Examples include:

• C83.0A (Small cell B-cell lymphoma, in remission)
• C83.3A (Diffuse large B-cell lymphoma, in remission)
• C84.6A (Anaplastic large cell lymphoma, ALK-positive, in remission)
• C84.7B (Anaplastic large cell lymphoma, ALK-negative, in remission)
• C85.1A (Unspecified B-cell lymphoma, in remission)
• C85.2A (Mediastinal (thymic) large B-cell lymphoma, in remission)

Significantly, the 2025 code set also expands the C86.- (Other specified types of T/NK-cell lymphoma) and C88.- (Malignant immunoproliferative diseases and certain other B-cell lymphomas) groups not only with “in remission” codes, this time indicated with 5th character 1, but also with “not having achieved remission” codes, indicated with 5th character 0. Examples here include such codes as:

• C86.00 (Extranodal NK/T-cell lymphoma, nasal type not having achieved remission)
• C86.01 (Extranodal NK/T-cell lymphoma, nasal type, in remission)
• C86.10 (Hepatosplenic T-cell lymphoma not having achieved remission)
• C86.11 (Hepatosplenic T-cell lymphoma, in remission)
• C88.20 (Heavy chain disease not having achieved remission)
• C88.21 (Heavy chain disease, in remission)
• C88.30 (Immunoproliferative small intestinal disease not having achieved remission)
• C88.31 (Immunoproliferative small intestinal disease, in remission)

Michael Shaughnessy, BA, CPC, Development Editor I