When coding with ICD-10-CM, pain codes can be found in different sections:

• The Body System affected or site-specific pain codes, such as Low Back Pain M54.5, can be found in Chapter 13. Diseases of the Musculoskeletal system (M00-M99). Other examples might be ocular pain H57.1, found in Chapter 7. Diseases of the eye and adnexa.

• If coding pain as a symptom such as R10 Abdominal and pelvic pain, see Chapter 18. Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99).
• Chapter 6. Diseases of the nervous system (G00-G99) has a category specifically for pain, G89. This code set is only to be used if there are no other codes to best describe the condition and include Acute, Chronic Pain and Neoplasm related pain.

• Pain due to an injury or complication is also common and can be found in Chapter 19. Injury, poisoning and certain other consequences of external causes (S00-T88). For example, pain due to a complication from an implant, T85.848 - Pain due to other internal prosthetic devices, implants and grafts.

Chronic Pain is a condition that can be diagnosed on its own or diagnosed as a part of another condition. Chronic pain is classified to subcategory G89.2. There is no time frame defining when pain becomes chronic pain. The provider’s documentation should be used to guide the use of these codes.

Codes from category G89 may be used in conjunction with codes that identify the site of pain (including codes from chapter 18) 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 should be assigned.

According to Section: 1;C.6.b, "The sequencing of category G89 codes with site-specific pain codes (including chapter 18 codes), is dependent on the circumstances of the encounter/admission as follows:

• If the encounter is for pain control or pain management, assign the code from category G89 followed by the code identifying the specific site of pain (e.g., encounter for pain management for acute neck pain from trauma is assigned code G89.11, Acute pain due to trauma, followed by code M54.2, Cervicalgia, to identify the site of pain).
• If the encounter is for any other reason except pain control or pain management, and a related definitive diagnosis has not been established (confirmed) by the provider, assign the code for the specific site of pain first, followed by the appropriate code from category G89."

The following codes are the most common pain codes used in ICD-10-CM

G89.0                     Central pain syndrome   Chronic Condition

G89.11‑G89.18      G89.1 Acute pain, not elsewhere classified

G89.21‑G89.29      G89.2 Chronic pain, not elsewhere classified

G89.3                     Neoplasm related pain (acute) (chronic) Chronic Condition

G89.4                     Chronic pain syndrome

There are more specific pain codes that define the encounter with more specificity, such as acute and chronic. Chronic Pain has no time frame defining the pain and can be reported when the condition is chronic pain.

Review the guidelines to understand when assigning pain as a symptom and when G codes are acceptable as the first listed diagnosis.

A code from category G89 should not be assigned if the underlying (definitive) diagnosis is known unless the reason for the encounter is pain control/ management and not the management of the underlying condition.

If the pain is not specified as acute or chronic, post-thoracotomy, postprocedural, or neoplasm-related, do not assign codes from category G89.

When an admission or encounter is for a procedure aimed at treating the underlying condition (e.g., spinal fusion, kyphoplasty), a code for the underlying condition (e.g., vertebral fracture, spinal stenosis) should be assigned as the principal diagnosis. No code from category G89 should be assigned.

G89.3 May be assigned as the first listed diagnosis or the principal diagnosis when the reason for the encounter is neoplasm related pain.