September 23, 2019

Assigning & Sequencing: Addressing Pain Codes

Codes to define pain were present in ICD-9-CM, first being published in 2006.  Prior to this, most alphabetical index entries directed the coder to index pain, by site or the underlying cause of the pain.  The codes were created specifically to reflect treatment of pain only, such in cases of pain management.  Although the guidelines have not changed through the years, there is still some confusion about coding and sequencing pain codes.

The first rule of successfully utilizing the pain codes is to follow the alphabetical and tabular index, and to understand the guidelines. 

In the alphabetical index under PAIN, there is a subheading for “acute” which leads the coder to code R52 Pain, Unspecified.  However, listed under R52 is a list of EXCLUDES 1 notes for acute and chronic pain, not elsewhere classified (G89.-) and also localized pain, unspecified type which directs the coder to code to pain, by site (i.e., abdominal pain R10.-; back pain M54.9, etc.)

Under the G89.- section, there are very specific entries for types of pain:

  • G89.0    Central Pain Syndrome
  • G89.1    Acute pain, not elsewhere classified
  • G89.11  Acute pain due to trauma
  • G89.12  Acute post-thoracotomy pain
  • G89.18  Other acute postprocedural pain
  • G89.2    Chronic pain, not elsewhere classified
  • G89.21  Chronic pain due to trauma
  • G89.22  Chronic post-thoracotomy pain
  • G89.28  Other chronic postprocedural pain
  • G89.29  Other chronic pain
  • G89.3    Neoplasm related pain (acute)(chronic)
  • G89.4    Chronic pain syndrome

Other than Central Pain Syndrome and Neoplasm Related Pain, correct code assignment relies on clear physician documentation of “acute” or “chronic” to assign a code from this section.    

When a patient presents and is admitted specifically for pain control, the coder may sequence the pain code as principal diagnosis (or first listed).  An example of this would be:  a patient with lung cancer (previously resected) with metastasis to brain and bone is admitted for treatment of his bone pain caused by the metastasis.  There is no treatment directed at the cancer itself (i.e., chemotherapy or radiation therapy) so the coder may sequence Neoplasm-related pain, G89.3, as the principle diagnosis followed by the neoplasm codes.  As evidenced by the tabular index, the physician does not need to specify whether the pain is acute or chronic, as both of these are designated nonessential modifiers after the code description.

If the patient presents for attention to the site of the pain for further clinical work-up or any reason other than primary pain control, then the site of the pain is coded, and depending on the documentation an additional code from the G89.- section may be used. 

For example: a patient has a fracture of the ulna and had recently undergone a reduction of the fracture with casting.  The patient returns with complaints of acute pain at the site of the fracture.  After x-ray it is found that the fracture has slightly displaced, so another reduction and casting is performed.  The code for the ulnar fracture would be sequenced first, and the code G89.11 Acute pain due to trauma may be coded as a secondary diagnosis. 

Likewise, if a patient presents to the emergency department for acute abdominal pain, it is not appropriate to assign a code from G89- as the physician did not specify the acute pain as being due to trauma, post-thoracotomy, or other postprocedural pain.  This is an instance where the coder would assign the code for site of the pain (abdomen) only.

There are two chronic pain codes, G89.2 Chronic pain, not elsewhere classified, and G89.4 Chronic pain syndrome, which is described as chronic pain associated with significant psychosocial dysfunction.  Pain with psychosocial dysfunction typically means pain that is so debilitating that it interferes with activities of daily living and has resulting psychological disorders such as depression.  Again, the physician documentation must be very clear in noting that the patient has chronic pain syndrome in order to assign this code.

In summary, pain codes can be very helpful in further defining the type or extent of pain a patient is experiencing and give a clear picture of the focus of treatment and utilization of resources.  The coder must carefully review the documentation in order to determine if it is appropriate to assign a code from category G89, and then which code within that category should be used.

Robyn McCoart, RHIT

Managing Auditor, Excite Health Partners