a. Dominant/nondominant side

Codes from category G81, Hemiplegia and hemiparesis, and subcategories G83.1, Monoplegia of lower limb, G83.2, Monoplegia of upper limb, and G83.3, Monoplegia, unspecified, identify whether the dominant or nondominant side is affected. Should the affected side be documented, but not specified as dominant or nondominant, and the classification system does not indicate a default, code selection is as follows:

• For ambidextrous patients, the default should be dominant.
• If the left side is affected, the default is non-dominant.
• If the right side is affected, the default is dominant.

b. Pain - Category G89

1) General coding information

Codes in category G89, Pain, not elsewhere classified, may be used in conjunction with codes from other categories and chapters to provide more detail about acute or chronic pain and neoplasm-related pain, unless otherwise indicated below.

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

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 management of the underlying condition.

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.

(a) Category G89 Codes as Principal or First-Listed Diagnosis

Category G89 codes are acceptable as principal diagnosis or the first-listed code:

• When pain control or pain management is the reason for the admission/encounter (e.g., a patient with displaced intervertebral disc, nerve impingement and severe back pain presents for injection of steroid into the spinal canal). The underlying cause of the pain should be reported as an additional diagnosis, if known.
• When a patient is admitted for the insertion of a neurostimulator for pain control, assign the appropriate pain code as the principal or first-listed diagnosis. When an admission or encounter is for a procedure aimed at treating the underlying condition and a neurostimulator is inserted for pain control during the same admission/encounter, a code for the underlying condition should be assigned as the principal diagnosis and the appropriate pain code should be assigned as a secondary diagnosis.

(b) Use of Category G89 Codes in Conjunction with Site Specific Pain Codes

(i) Assigning Category G89 and Site-Specific Pain 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. (ii) Sequencing of Category G89 Codes with Site-Specific Pain Codes 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.

2) Pain due to devices, implants and grafts

See Section I.C.19. Pain due to medical devices

3) Postoperative Pain

The provider's documentation should be used to guide the coding of postoperative pain, as well as Section III. Reporting Additional Diagnoses and Section IV. Diagnostic Coding and Reporting in the Outpatient Setting. The default for post-thoracotomy and other postoperative pain not specified as acute or chronic is the code for the acute form. Routine or expected postoperative pain immediately after surgery should not be coded.

(a) Postoperative pain not associated with specific postoperative complication

Postoperative pain not associated with a specific postoperative complication is assigned to the appropriate postoperative pain code in category G89.

(b) Postoperative pain associated with specific postoperative complication

Postoperative pain associated with a specific postoperative complication (such as painful wire sutures) is assigned to the appropriate code(s) found in Chapter 19, Injury, poisoning, and certain other consequences of external causes. If appropriate, use additional code(s) from category G89 to identify acute or chronic pain (G89.18 or G89.28).

4) Chronic pain

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 use of these codes.

5) Neoplasm Related Pain

Code G89.3 is assigned to pain documented as being related, associated or due to cancer, primary or secondary malignancy, or tumor. This code is assigned regardless of whether the pain is acute or chronic.

This code may be assigned as the principal or first-listed code when the stated reason for the admission/encounter is documented as pain control/pain management. The underlying neoplasm should be reported as an additional diagnosis.

When the reason for the admission/encounter is management of the neoplasm and the pain associated with the neoplasm is also documented, code G89.3 may be assigned as an additional diagnosis. It is not necessary to assign an additional code for the site of the pain.

See Section I.C.2 for instructions on the sequencing of neoplasms for all other stated reasons for the admission/encounter (except for pain control/pain management).

6) Chronic pain syndrome

Central pain syndrome (G89.0) and chronic pain syndrome (G89.4) are different than the term "chronic pain," and therefore codes should only be used when the provider has specifically documented this condition. See Section I.C.5. Pain disorders related to psychological factors