The Must Know 2024 ICD-10 Code Updates for Physical Therapists

Not often does an ICD-10-CM announcement come with much appreciation or fanfare, but perhaps this year is different for rehab therapists. Healthcare professionals who treat the musculoskeletal system and must assign a specific code for lumbar disc degeneration or a synovitis issue can attest to the relative ambiguity inherent with ICD-10-CM coding in the past. Well, that is about to change as of October 1, 2024. In previous years, ICD-10-CM used the codes M51.36 (other intervertebral disc degeneration, lumbar region), M51.37 (other intervertebral disc degeneration, lumbosacral region), and M65.9 (synovitis and tenosynovitis, unspecified). However, as many clinicians have been finding, using diagnosis codes that are “unspecified” can lead to some issues in claim denials and proper coding for specificity. 

So, to improve the accuracy of coding, the Centers for Medicare and Medicaid Services (CMS) have elected to add a slew of new ICD-10-CM codes that will go into effect on October 1, 2024, while the three unspecified codes will be deleted. These changes directly affect physical therapy practices—so we’re here with all the details to help physical therapy clinicians stay ahead of the curve and continue to deliver stellar patient outcomes.

What codes will replace M51.36?

The code M51.36 (other intervertebral disc degeneration, lumbar region) is a fairly common ICD-10 code used for patients experiencing low back pain (LBP) in the lumbar region due largely to degenerative processes of intervertebral discs. Although many healthcare providers would encourage these diagnoses to steer away from deleterious terms like degenerative, they most accurately describe the etiology of the patient’s condition when disc degeneration is the suspected prime cause. 

But to give an accurate ICD-10 diagnosis code, including the word unspecified doesn’t exactly scream specific—in fact, it is just the opposite. The new codes will hopefully add some specificity when rehab therapists opt to use codes associated with lumbar disc degeneration as a primary—or secondary—ICD-10-CM code. The new codes are as follows:

• 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); and
• M51.369 (other intervertebral disc degeneration, lumbar region without mention of lumbar back pain or lower extremity pain).

Digging a bit deeper into the codes and the new changes to specificity, the primary changes adhere to the presence of LBP, leg pain, or the absence of either. The codes do not afford right or left differentiation, but appear to be a step in the right direction and will coincide well with the newest clinical practice guidelines for treating LBP.

What codes will replace M51.37?

ICD-10-CM code M51.37 is similar to the M51.36 but applies to disc degeneration pathologies of the lumbosacral region. So, get out your myotomes and dermatomes tables from physical therapy school and refresh yourself on which patients would fit under lumbar versus lumbosacral. Ensuring that you assign the most accurate and specific code—and differentiate between lumbar and lumbosacral disc degeneration—will help you establish the medical necessity a given patient has for physical therapy services.

These are the new codes that will replace M51.37: 

• M51.370 (other intervertebral disc degeneration, lumbar region with discogenic back pain only);
• M51.371 (other intervertebral disc degeneration, lumbar region with lower extremity pain only);
• M51.372 (other intervertebral disc degeneration, lumbar region with discogenic back pain and lower extremity pain); and
• M51.379 (other intervertebral disc degeneration, lumbar region without mention of lumbar back pain or lower extremity pain); and
• M62.85 (dysfunction of the multifidus muscles, lumbar region).

Interestingly, M62.85 (dysfunction of the multifidus muscles, lumbar region) could be applied to the lumbar or lumbosacral region, so use your clinical judgment when applying this ICD-10-CM code. There exists a wealth of research linking lumbar multifidus dysfunction to spinal degeneration—specifically in cases of non-specific low back pain, so physical therapy patients that fit under this umbrella may be best served by the intended M62.85 ICD-10 code.

What codes will replace M65.9?

If a physical therapist (or occupational therapist) uses M65.9 (synovitis and tenosynovitis, unspecified), this could be one of the most vague ICD-10-CM codes available. Why? Well because synovial membranes exist throughout the entirety of the musculoskeletal system. So, when a physical therapist wants to advocate for a patient to receive care for their hip or ankle synovitis, this code has not historically lent itself to painting a specific picture of what is going on with the patient. 

Instead, clinicians might have chosen something like M25.571 to describe right ankle pain, but this could additionally lend itself to some issues with accurately describing the patient’s functional deficits and medical necessity for physical therapy at the initial encounter.

So to try and give a bit more clarity to ICD-10-CM diagnoses that deal with synovitis, these new codes will replace M65.9:

• M65.90 (unspecified synovitis and tenosynovitis, unspecified site);
• M65.911 (unspecified synovitis and tenosynovitis, right shoulder);
• M65.912 (unspecified synovitis and tenosynovitis, left shoulder);
• M65.919 (unspecified synovitis and tenosynovitis, unspecified shoulder);
• M65.921 (unspecified synovitis and tenosynovitis, right upper arm);
• M65.922 (unspecified synovitis and tenosynovitis, left upper arm);
• M65.929 (unspecified synovitis and tenosynovitis, unspecified upper arm);
• M65.931 (unspecified synovitis and tenosynovitis, right forearm);
• M65.932 (unspecified synovitis and tenosynovitis, left forearm);
• M65.939 (unspecified synovitis and tenosynovitis, unspecified forearm);
• M65.941 (unspecified synovitis and tenosynovitis, right hand);
• M65.942 (unspecified synovitis and tenosynovitis, left hand);
• M65.949 (unspecified synovitis and tenosynovitis, unspecified hand);
• M65.951 (unspecified synovitis and tenosynovitis, right thigh);
• M65.952 (unspecified synovitis and tenosynovitis, left thigh);
• M65.959 (unspecified synovitis and tenosynovitis, unspecified thigh);
• M65.961 (unspecified synovitis and tenosynovitis, right lower leg);
• M65.962 (unspecified synovitis and tenosynovitis, left lower leg);
• M65.969 (unspecified synovitis and tenosynovitis, unspecified lower leg);
• M65.971 (unspecified synovitis and tenosynovitis, right ankle and foot);
• M65.972 (unspecified synovitis and tenosynovitis, left ankle and foot);
• M65.979 (unspecified synovitis and tenosynovitis, unspecified ankle and foot); and
• M65..98 (unspecified synovitis and tenosynovitis, other site).

What is the difference between synovitis/tenosynovitis and tendonitis?

In bringing up the diagnosis of synovitis, physical therapists must be sure to differentiate between synovitis/tenosynovitis and tendonitis. Specifically, tenosynovitis is the inflammation of the synovial membrane encasing a tendon, while tendonitis is the inflammation of the tendon itself. As such, there are often more common areas that are affected by tenosynovitis. Many physical therapists (or occupational therapists) will likely think of the hand where De Quervain's tenosynovitis commonly affects the synovial sheaths of muscle tendons in the thumb. So, when deciding which ICD-10-CM diagnosis code to use, be mindful of your anatomy and the structures involved.

How can you prepare for the ICD-10-CM code changes?

In preparation for the new ICD-10-CM codes to go into effect—and the old ones to be deleted—make sure you understand the what and how of ICD-10 coding for diagnoses in physical therapy practice. Proper code selection largely rests on the clinical judgment of the evaluation physical therapist, but there are also a series of guidelines to help you along the way. It also helps to have a documentation system that is ready for changes in real time. That means a cloud-based EMR that prides itself on being ahead of compliance and regulatory changes. This will ensure that your documentation is up to date and ready to submit for Medicare reimbursement or any other insurance payer. In the meantime, you can count on WebPT to always stay abreast of the healthcare landscape and keep the rehab therapy industry in the know on any changes, updates, and whatever else regulators want to throw at physical therapists.