Low back pain is one of the most common reasons patients see a physical therapist, chiropractor or physician, so it is also one of the most common diagnosis codes on therapy claims. Picking the wrong one, or still using the old M54.5, is an easy way to get a claim denied. This guide covers which code to use, the related codes you will see most often, and how to document low back pain so your claims go through the first time.
Key Takeaways
- The Medicare 8-minute rule lets you bill one unit of a timed CPT code when you provide at least 8 minutes of direct, one-on-one treatment.
- Units are based on the total timed minutes in the visit: 8–22 minutes = 1 unit, 23–37 = 2 units, 38–52 = 3 units, then 1 more unit for every 15 minutes.
- When you perform several timed codes, give units to the codes with the most minutes first, then assign any remaining unit to the service with the most leftover minutes.
- Untimed (service-based) codes, such as evaluations, don’t count toward your timed minutes.
- Medicare and many Medicaid plans use the 8-minute rule. Some commercial payers count each code separately (the “rule of eights”), so check each payer’s policy.
- Document the timed minutes for each code to support every unit you bill.
Table of Contents
What Is the ICD-10 Code for Lower Back Pain?
Use M54.50 (low back pain, unspecified) when the cause is not documented, M54.51 (vertebrogenic low back pain) when imaging shows vertebral endplate changes, and M54.59 (other low back pain) for a documented cause that has no more specific code. The old code M54.5 is now a category header and cannot be billed.
| Code | Description | Use it when |
|---|---|---|
|
M54.50 |
Low back pain, unspecified |
The cause of the pain is not documented. Also covers lumbago NOS and loin pain. |
|
M54.51 |
Vertebrogenic low back pain |
Imaging (usually MRI) shows vertebral endplate changes, such as Modic type 1 or 2 changes, and the pain is linked to them. |
|
M54.59 |
Other low back pain |
The low back pain has a documented cause or type that no more specific code describes. |
M54.50 vs M54.51 vs M54.59: Lower Back Pain ICD-10 Codes at a Glance
Hover over a card to reveal the description. On mobile, tap a card.
M54.50: Low back pain, unspecified
M54.50 is the general low back pain code. It fits a first visit where you have not yet identified a cause, or a referral that only says “low back pain.” It is a valid, billable code, but some payers look harder at unspecified codes, especially over a long plan of care. If your evaluation finds a more specific cause, update the diagnosis.
M54.51: Vertebrogenic low back pain
M54.51 describes pain that comes from the vertebral endplates, the layers of cartilage and bone above and below each disc. It is usually confirmed with an MRI showing Modic changes. Use it only when the imaging and the provider’s documentation support it, not just because the pain is in the lumbar spine.
M54.59: Other low back pain
M54.59 covers low back pain that has been characterized but has no more specific code of its own. Before you use it, check that a more specific code does not fit better, such as a strain (S39.012-), sciatica (M54.3-) or a disc condition (M51.-).
What Happened to M54.5?
M54.5 was retired as a billable code on October 1, 2021. It became a category header, and claims must now use M54.50, M54.51 or M54.59. A claim with M54.5 alone for a date of service on or after that date will be rejected.
Every October 1, the ICD-10-CM code set is updated with new, deleted and revised codes. The 2022 update (effective October 1, 2021) split low back pain into three codes so payers and providers could tell nonspecific pain apart from vertebrogenic pain. CMS listed the change in its 2022 ICD-10-CM files.
If M54.5 still shows up in your system, it is usually coming from:
- an old intake template or diagnosis favorites list
- a plan of care that was copied forward from before October 2021
- a referral from a provider whose system was never updated
Search your templates and active plans of care for “M54.5” and replace it with the right five-character code.
Related Low Back ICD-10 Codes
Many patients with low back pain have a more specific diagnosis. Coding to the highest level of detail you can support is what payers expect. These are the related codes therapy clinics use most:
| Condition | ICD-10 code | Notes |
|---|---|---|
|
Lumbago with sciatica |
M54.40 (unspecified side), M54.41 (right), M54.42 (left) |
Back pain plus sciatic leg pain. Do not also bill M54.5-. |
|
Sciatica (without low back pain) |
M54.30 (unspecified side), M54.31 (right), M54.32 (left) |
Leg pain along the sciatic nerve. |
|
Lumbar radiculopathy |
M54.16 (lumbar), M54.17 (lumbosacral) |
Nerve root symptoms without a coded disc cause. |
|
Disc disorder with radiculopathy, lumbar |
M51.16 |
Disc cause documented, with radiculopathy. |
|
Low back strain |
S39.012A, S39.012D, S39.012S |
Strain of muscle, fascia and tendon of the lower back. The 7th character is A (initial), D (subsequent) or S (sequela). |
|
Lumbar spinal stenosis |
M48.061 (without neurogenic claudication), M48.062 (with) |
|
|
Lumbar spondylosis |
M47.816 |
Without myelopathy or radiculopathy. |
|
Thoracic spine pain |
M54.6 |
Mid back, not low back. |
|
Dorsalgia, unspecified |
M54.9 |
Back pain with no region documented. Avoid when |
|
|
|
you know the region. |
The 2024 Disc Degeneration Codes (M51.36- and M51.37-)
On October 1, 2024, the old codes M51.36 and M51.37 became category headers. They were replaced with codes that say what kind of pain the patient has:
| Lumbar | Lumbosacral | Description |
|---|---|---|
|
M51.360 |
M51.370 |
Disc degeneration with discogenic back pain only |
|
M51.361 |
M51.371 |
Disc degeneration with lower extremity pain only |
|
M51.362 |
M51.372 |
Disc degeneration with discogenic back pain and lower extremity pain |
|
M51.369 |
M51.379 |
Disc degeneration without mention of back pain or lower extremity pain |
Because the back pain is now built into these codes, you no longer add a separate low back pain code to describe it.
Codes You Cannot Bill Together
ICD-10-CM uses “Excludes1” notes for codes that should never be reported together. These are the ones that trip up low back pain claims:
| If you use | Do not also use |
|---|---|
|
M54.5- (M54.50, M54.51, M54.59) |
M54.4- (lumbago with sciatica), S39.012- (low back strain), M51.2- (lumbago due to disc displacement), M51.360 or M51.370 (disc degeneration with back pain only) |
|
M54.4- (lumbago with sciatica) |
M51.362 or M51.372 (disc degeneration with back and leg pain) |
If two of these describe your patient, pick the one that best matches the documented diagnosis. For example, a patient with low back pain and sciatica gets M54.4-, not M54.50 plus M54.3-.
Is There an ICD-10 Code for Chronic Low Back Pain?
No. ICD-10-CM has no single code for chronic low back pain. Code the type of low back pain (usually M54.50 or M54.59) and add G89.29 (other chronic pain) when the documentation supports chronic pain. Use G89.4 (chronic pain syndrome) only when the provider documents chronic pain syndrome.
Which code goes first depends on why the patient is being seen. Under the ICD-10-CM guidelines, a G89 code is listed first when the main reason for the visit is pain control or pain management. When the visit is for the underlying condition, the site code (M54.5-) goes first. “Intractable” and “severe” back pain do not have their own codes either; describe them in your documentation.
How to Document Low Back Pain to Avoid Denials
The more specific your documentation, the easier it is to choose the right code and defend it if a payer asks.
Record what supports the code
- Onset, location (lumbar or lumbosacral) and whether pain travels into the leg
- Side (left, right or both) for sciatica and radiculopathy
- Imaging findings, if any, especially for M54.51 and the M51.36- and M51.37- codes
- Mechanism of injury for strains, so the S39.012- code and its 7th character are clear
- Duration, if the pain is chronic
FREE DOWNLOAD
Free Chiropractic New Patient Intake Form
The right low back pain code starts with a good intake. Our free 2-page form captures where the pain is, when it started, whether it travels into the leg and on which side, so you have what you need to code M54.50, M54.51, M54.59 or sciatica correctly from the first visit.
Printable PDF + editable Word file, sent straight to your inbox.
Clean up your templates and EMR
Remove M54.5 and M51.36 or M51.37 from diagnosis favorites, intake forms and saved plans of care. Check that your EMR and billing system use the current ICD-10-CM edition each October.
Train the whole team
Front desk, billing staff and clinicians all touch the diagnosis. A short review each October, when the code set changes, prevents most avoidable denials. Our guide to defensible documentation in physical therapy covers the wider documentation habits payers look for.
Two quick examples
- Example 1: A patient has had low back pain for two weeks after lifting a heavy box. The evaluation shows muscle guarding with no leg symptoms. The documented diagnosis is a low back strain, so code S39.012 with the right 7th character, not M54.50.
- Example 2: A patient has chronic low back pain, and the referral includes an MRI showing Modic type 1 changes linked to the pain. Code M54.51, and add G89.29 if chronic pain is documented and relevant to the visit.
How HelloNote Helps You Code Low Back Pain Correctly
HelloNote keeps diagnosis codes inside the plan of care and the note, so the code on the claim matches what the clinician documented. Instead of typing codes from memory, clinicians search and select current ICD-10 codes, which helps keep retired codes like M54.5 off new claims. Because notes, codes and billing live in one system, your team can spot a diagnosis that does not match the documentation before the claim goes out.
Frequently Asked Questions
What is the ICD-10 code for lower back pain?
The ICD-10 code for lower back pain is M54.50 (unspecified), M54.51 (vertebrogenic) or M54.59 (other low back pain). Choose the one that matches the documented cause.
Is M54.5 still a valid ICD-10 code?
No. M54.5 has not been billable since October 1, 2021. It is now a category header for M54.50, M54.51 and M54.59.
What is the ICD-10 code for lumbago?
Lumbago without further detail is coded M54.50. Lumbago with sciatica is coded M54.40, M54.41 or M54.42, depending on the side.
What is the ICD-10 code for low back pain with sciatica?
Use M54.41 for the right side, M54.42 for the left side and M54.40 when the side is not documented. Do not add M54.50 on top.
What is the difference between M54.50 and M54.59?
M54.50 is used when the cause of the low back pain is not documented. M54.59 is used when the pain has been characterized but no more specific code applies.
Did the low back pain codes change in 2026?
No. M54.50, M54.51 and M54.59 are unchanged in the 2027 ICD-10-CM edition, effective October 1, 2026. The most recent related change was the lumbar and lumbosacral disc degeneration codes (M51.36- and M51.37-) on October 1, 2024.
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