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Ultimate Guide to CPT Code 64999

Have you wondered whether the technique you are using to treat neurological disorders exists in the CPT book or not? If no CPT code can represent your procedure, how will you report your services? That is when CPT code 64999 comes to the rescue. If you cannot find an applicable CPT code for the neurological procedure, you can report your services with this catch-all code.

This code is used to bill unlisted procedures on the nervous system. However, its billing requires a lot of expertise and systematic preparation. This blog can help in the correct billing of this code. Let’s see what the right approach is to bill this code.

CPT Code 64999 – Description

If you have performed a less common procedure on the nervous system (brain, spinal cord, and nerves) that is not yet represented by a CPT code, it does not mean you cannot claim your payment. For such cases, the American Medical Association (AMA) has created CPT code 64999, which can be found in the ‘Other Procedures of the Nervous System’ codeset.

​You can report CPT code 64999 when a nervous system procedure lacks a more precise CPT code. This can occur for various reasons, including technological advancements and complex or uncommon operations on peripheral nervous systems that are not currently covered. 

Scenarios Where CPT Code 64999 is Applicable

What are the possible cases where you can apply CPT code 64999? Let’s explore this through some clinical examples.

Facet Joint Denervation

Suppose a 60-year-old man is suffering from chronic lower back pain because of facet joint degeneration. The physician takes a detailed history of his pain patterns, which reveals that he has tried various other treatments that did not help him cure his pain. So now, the physician decides to perform a facet joint denervation. 

During this procedure, the physician uses a neurolytic agent to destroy the small nerves that transmit pain signals from the damaged joint to the brain. It provides long-term pain relief for the patient because he did not respond well to other treatments. Since the physician performed facet joint denervation without using any imaging technique, he must bill his service with CPT   code 64999. Because the available CPT codes 64633 and 64635 cover the procedure with image guidance. 

Erector Spinae Plane Block

Let’s think of another scenario where a 35-year-old patient undergoes a lumbar spine surgery. After the surgery, the physician injects the erector spinae plane (ESP) block in the lumbar region for pain relief from postoperative pain. 

He uses ultrasound to guide a needle to a specific lumbar level. The needle is advanced to the corner of the transverse process. A local anesthetic is injected into the fascial plane superficial to the transverse process and deep to the erector spinae muscle. The procedure provides pain relief. Since there is no specific CPT code to bill this procedure, you can apply CPT code 64999 for the performance of these services.

Applicable Modifiers for CPT Code 64999

Most often, modifiers are not required for unlisted codes like CPT 64999. However, in the case of facet joint interventions, payers may require that the procedure be specified as to which side of the body it was performed on. In such cases, you will have to append the laterality modifiers to CPT code 64999. 

Modifier LT

This modifier explains to the insurance payer that the unlisted procedure was performed on the left side of the body. 

Modifier RT

In contrast, modifier RT specifies that the procedure was performed on the right side of the body. 

Modifier 50

However, if the nervous system procedure was performed on both sides of the body during the same surgical session, you will append modifier 50 to CPT code 64999 to indicate bilaterality. 

CPT Code 64999 – Billing & Reimbursement Guidelines

Since CPT code 64999 is an unspecified or unlisted code, you must stay vigilant while billing it. Unnecessarily reporting unlisted CPT codes for reimbursement purposes is perceived as a coding error. And coding errors trigger denials. 

Below are some billing and reimbursement guidelines you may follow. 

Understand the Intricacies of the Code

When billing CPT code 64999, it is essential to understand its proper use. This code should not be used simply because you are unable to find the code that most specifically describes the nervous system procedure. That is an incorrect approach.

Instead, determine when its use is justified. For example, the administration of erector spinae plane blocks was often billed as 64999. But the American Society of Anesthesiologists (ASA) introduced CPT codes 64466 to 64489 for thoracic fascial plane blocks, paravertebral spinal nerve blocks, and transversus abdominis plane blocks in 2025. 

So the physicians cannot bill their services with CPT 64999 in thoracic regions. However, since this update does not apply to the lumbar region, the physicians can bill the erector spinae plane blocks for the lumbar region with CPT code 64999.

Meet the Documentation Requirements

The more difficult the code, the more imperative its documentation is. The following are the key requirements that you must be mindful of when attaching supporting documentation to your 64999 claims. 

  • Every page of the patient’s medical record must be legible and include appropriate patient identification information, e.g., complete name, insurance policy number, and date of service.
  • A clear indication of the patient’s condition, symptoms, or diagnosis that required the procedure.
  • Description of the procedure and the technique used.
  • Legible signature of the physician or non-physician practitioner responsible for and providing the care to the patient.
  • The submitted medical record must support the use of the selected ICD-10-CM codes. 

Follow the Payers’ Specific Guidelines

Lastly, stay up-to-date with the changes in insurance payers’ policies. Before submitting claims with CPT code 64999, ensure that your patient’s insurance payer covers the code. For instance, Medicare does not cover this code for auricular peripheral nerve stimulation and non-thermal facet joint denervation. So you must check the procedure’s coverage before submitting claims to insurance payers. Otherwise, you may receive a denial, causing delayed payment and wasted resources.

Final Word

In short, you can still successfully bill CPT code 64999 with proper understanding and execution. Let’s recap whatever we learned in this guide. This code is used to report unlisted procedures on the nervous system. There are very few cases where you can successfully bill this code; a couple of them include:

  • Erector Spinae Plane Block for the lumbar region
  • Facet Joint Denervation without imaging

In the ‘Billing & Reimbursement Guidelines’ section, we have covered all the essential points you must keep in mind while billing code 64999.

However, considering the complexity of the code, we recommend acquiring professional neurosurgery billing services. Experts offering such specialized services are adept at submitting claims for unlisted codes. 

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