Primary Care Coding Alert

Find out when it’s appropriate to use codes from the G89.- category.

Low back pain codes continue to give coders trouble, and with good reason: it’s been less than a year since three new codes were added to ICD-10. Read on for guidance on when and how to report them.

Identify Whether the Pain Is Vertebrogenic or Discogenic

“Chronic low back pain frequently stems from the vertebrae itself, which is referred to as vertebrogenic back pain. Pain that originates at the disc is called discogenic,” as defined by Neurosurgery One. To help coders report patient care to the highest specificity, ICD-10 2022 divided M54.5 (Low back pain) into three new codes that take this definition into account:

• M54.50 (Low back pain, unspecified)
• M54.51 (Vertebrogenic low back pain)
• M54.59 (Other low back pain)

Code M54.50 includes loin pain and low back pain (lumbago) not otherwise specified (NOS), M54.51 includes low back vertebral endplate pain, and you should use M54.59 for specified low back pain that’s not in the vertebrae. It’s very possible, especially at a first encounter, that the exact source of the pain won’t be known, which will likely lead to the unspecified code, M54.50. “The correct diagnosis code depends in large part on the extent to which the documentation identifies the site and type of pain,” explains

Kent Moore, senior strategist for physician payment at the American Academy of Family Physicians.

It’s also important to notice the following as Excludes1 diagnoses for M54.5- codes:

• S39.012- (Strain of muscle, fascia and tendon of lower back);
• M51.2- (Other thoracic, thoracolumbar and lumbosacral intervertebral disc displacement); and
• M54.4- (Lumbago with sciatica).

“Per the Excludes1 note, some lumbago is classified elsewhere,” Moore points out. Lumbago is a general term often used for pain in the lower back, so you should pay attention to the patient record carefully, and query the provider if questions arise. Additionally, “note that lumbago NOS is the only lumbago coded to M54.50,” says Moore.

Avoid the Temptation to Heavily Rely on G89.-

Adding an unnecessary G89.- (Pain, not elsewhere classified) code to a back pain diagnosis is an easy mistake to make, especially if you follow ICD-10-CM Official Guidelines, Section I.C.6.b.1(b)(i), which states, “Codes from category G89 may be used in conjunction with codes that identify the site of pain (including codes from chapter 18 [Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)]) if the category G89 code provides additional information. For example, if the code describes the site of the pain, but does not fully describe whether the pain is acute or chronic, then both codes [a G89 code and site-specific code] should be assigned.”

Consistent with that guideline, “M54.5- is among a long list of Excludes2 notes under G89.-. That means low back pain is a separate diagnosis from G89.-, and G89.- should not be used for low back pain per se. However, if the patient has both low back pain and pain not elsewhere classified, or if a category G89.- code provides additional information, then codes M54.5- and G89.- may both be used,” says Moore.

Use This Guideline to Assign Codes for Trauma or Surgery

If the patient’s back pain is a result of an injury or the side effect of an invasive medical procedure, code assignment will then be subject to ICD-10 guideline I.C.13.b., which states that recurrent bone, joint, or muscle conditions, including those that are the result of a healed injury, are usually found in Chapter 13, Diseases of the musculoskeletal system and connective tissue (M00-M99).

The guideline goes on to state “any current, acute injury should be coded to the appropriate injury code from chapter 19 [Injury, poisoning and certain other consequences of external causes (S00-T88)]. Chronic or recurrent conditions should generally be coded with a code from chapter 13. If it is difficult to determine from the documentation in the record which code is best to describe a condition, query the provider.” In other words, if the source of the current, acute pain is known, and that source is an injury (for example, S33.5XXA (Sprain of ligaments of lumbar spine, initial encounter)), the injury itself is the most appropriate condition to code in these instances.

Encourage Specificity for Better Coding and Patient Care

“Pain typically falls under acute or chronic,” explains Maureen Leahey, CHC, CPC, primary care coding team leader with Sentara Healthcare in Norfolk, Virginia. “With acute diagnoses, the cause is typically known, such as a car accident. In chronic diagnoses, cause is not always known. It is ongoing and can influence functional or structural changes in the peripheral or central nervous systems,” Leahey says. However, whether the pain is acute or chronic is not up to the coder’s interpretation. Those distinctions are made by the provider. “We always code what we see. Encourage your provider to be as specific as he/she can when treating pain,” continues Leahey.

Keep it simple: As for which code to rely on when reporting acute or chronic low back pain specifically, the key is to not overcomplicate things. “For pain that is classified elsewhere, whether acute or chronic, start with the more site-specific code. In the case of M54.-, there’s no indication of separate coding for chronic versus acute, so I believe the same code can be used for either,” says Moore.

You won’t always find a distinction between acute and chronic pain in the patient record, but the provider should document as much detail as possible because it always leads to the ability to code to the highest specificity. “The biggest challenge is the level of detail in the note. When working in the primary care setting, there can be many instances of unspecified. For these new additions, the more details, the better — for more accurate coding and fewer reasons for denial. If the provider has images confirming degenerative disc disease, spinal stenosis, or a herniated disc, for example, these would be better [diagnosis] options to use since the condition would be the cause of the pain,” says Leahey.