CPT Code 64493: Complete Guide to Lumbar Facet Joint Injection Billing

Back pain is one of the most common reasons patients visit doctors. For those dealing with persistent lower back pain that doesn’t respond to conservative treatments, lumbar facet joint injections often become part of the solution. These procedures are both diagnostic and therapeutic — and when performed correctly, they can confirm the source of pain and provide meaningful relief.

When a provider injects a medication into a single level of the lumbar or sacral spine, CPT code 64493 is used to report that service. This article explains what CPT 64493 is, when to use it, how to bill it accurately, what documentation is required, and what common mistakes to avoid. Whether you’re a coder, provider, or pain management billing manager, this guide is designed to help you get 64493 right — every time.

What Is CPT Code 64493?

The CPT Code  64493 represents an injection into the paravertebral facet joint (or the nerves that supply the joint) in the lumbar or sacral spine, performed under fluoroscopic or CT guidance. This injection may be used to either diagnose or treat pain originating from the facet joint.

It is defined as:

Injection(s), diagnostic or therapeutic agent, paravertebral facet (zygapophyseal) joint (or nerves innervating that joint) with image guidance (fluoroscopy or CT), lumbar or sacral; single level.

The keyword here is single level. If more than one level is injected in the same session, add-on codes like 64494 or 64495 are used in addition to 64493.

Clinical Context: Why Lumbar Facet Injections Are Performed

The facet joints are small stabilizing joints located between and behind adjacent vertebrae. They help guide movement and limit rotation. When these joints become inflamed due to degeneration, arthritis, or injury, they can cause localized pain — often referred to as facet-mediated pain.

Reasons for facet joint injections include:

  • Persistent axial lower back pain not responding to physical therapy or medications

  • Diagnostic testing to identify the pain generator

  • Therapeutic relief when other conservative approaches have failed

Often, the goal is not just temporary relief. If a facet joint is confirmed as the pain source through successful diagnostic injections, the patient may be a candidate for radiofrequency ablation (RFA) — a procedure that offers longer-term relief.

64493 and Its Place in the Code Set

CPT 64493 is part of a code family used to describe facet injections by spinal region and number of levels. Here’s how it fits:

Code

Region

Level

Description

64490

Cervical/Thoracic

First level

Facet joint injection

64491

Cervical/Thoracic

Second level

Add-on code

64492

Cervical/Thoracic

Third+ level

Add-on code

64493

Lumbar/Sacral

First level

Primary code

64494

Lumbar/Sacral

Second level

Add-on code

64495

Lumbar/Sacral

Third+ level

Add-on code

Use 64493 only for the first level injected in the lumbar or sacral region during a given session. For example, if the provider performs facet injections at L4-L5 and L5-S1, you would report:

  • 64493 (first level)
  • 64494 (second level)

Image Guidance: A Mandatory Requirement

One key detail in the code definition is image guidance — either fluoroscopy or CT must be used and documented. This is not optional. Without it, CPT 64493 is not billable.

Ultrasound, even if used, does not meet the imaging guidance requirement for this code. Be sure that the provider’s documentation clearly states:

  • Type of imaging used (fluoroscopy or CT)
  • Confirmation of needle placement
  • Anatomical level injected

When to Use CPT 64493

Use 64493 when:

  • The provider performs a facet joint injection at a single level in the lumbar or sacral region

  • Image guidance is used and documented

  • The procedure is performed for diagnostic or therapeutic purposes

Example:


A provider injects a mixture of steroid and anesthetic into the right L4-L5 facet joint under fluoroscopy.
Report: 64493

If the provider also treats L5-S1 during the same session, you would also report 64494.

Modifier Use With 64493

Proper modifier use ensures clean claim processing and accurate reimbursement. Here’s what you need to know:

  • Modifier 50 (Bilateral Procedure): Use if both sides of the same level are injected. Report 64493-50 on a single line.

  • Modifiers RT and LT (Right/Left): Some payers prefer separate lines for each side. For example:

    • 64493-RT

    • 64493-LT

Do not use modifier 51 with 64493. It is a primary code and does not require multiple procedure reduction logic.

Billing Examples

Single Level, Unilateral Injection

  • Right L4-L5, fluoroscopic guidance
    Code: 64493

Single Level, Bilateral Injection

  • Both sides of L4-L5, fluoroscopic guidance
    Code: 64493-50
    (or two lines with RT and LT depending on payer)

Two-Level Injections

  • L4-L5 and L5-S1
    Codes:

  • 64493

  • 64494

Three-Level Bilateral Injections

  • Bilateral L3-L4, L4-L5, L5-S1
    Codes:

  • 64493-50

  • 64494 x2

  • 64495 x2
    (Depending on payer billing rules, modifiers may vary)

Documentation Checklist

To support CPT 64493, the provider’s note must include:

 ✅ Pain history — duration, location, severity
✅ Prior conservative treatments and failure documentation
✅ Indication for injection — diagnostic or therapeutic
✅ Specific spinal level treated (e.g. L4-L5)
✅ Laterality — right, left or bilateral
✅ Image guidance type used (fluoroscopy or CT)
✅ Immediate patient response, if diagnostic

Medicare Coverage and Medical Necessity

Medicare has specific requirements for facet injections, particularly for diagnosis-driven coverage. Some key rules include:

  • Pain must be chronic and axial, lasting 3+ months
  • Must show functional impairment based on clinical notes or pain scales
  • Must have failed conservative management
  • For therapeutic injections, the patient must have had two diagnostic injections at the same level showing at least 80% pain relief

Frequency Limits (Medicare)

  • No more than 4 diagnostic sessions per spinal region in a 12-month rolling period
  • No more than 4 therapeutic sessions per region per year
  • For RFA procedures, no more than 2 sessions per region in 12 months

Documentation must reflect these criteria clearly — otherwise claims may be denied.

Reimbursement Snapshot for CPT 64493

Reimbursement varies by payer, setting, and location. Below are average national figures:

Payer Type

Site of Service

Approx. Reimbursement

Medicare

Ambulatory Surgical Center (ASC)

$112

Medicare

Hospital Outpatient Dept (HOPD)

$195

Commercial Plans

Office Setting (Physician)

$140–$280

Keep in mind that contracts, bundling, and modifiers affect these figures.

Common Denials and How to Avoid Them

Reason for Denial

Fix It Strategy

Missing image guidance documentation

Add fluoroscopy or CT confirmation in op note

Billed without medical necessity

Include failed conservative therapy details

Modifier misuse

Use 50 or RT/LT as required by payer

Using 64493 as an add-on code

It is a primary code and must come first

Missing pain assessment

Add disability or pain scale rating

 

Final Thoughts

CPT 64493 may seem simple at first glance — a single-level lumbar injection — but its correct usage requires attention to clinical necessity, imaging, modifiers, and payer rules. Errors in documentation or sequencing can easily lead to denials.

To stay compliant and reduce billing delays:

  • Know the clinical criteria
  • Document imaging use clearly
  • Understand payer modifier preferences
  • Use code combinations properly when treating multiple levels

When used correctly, 64493 supports quality pain care and accurate reimbursement — helping your practice serve patients better and bill cleaner.

FAQ: CPT 64493

Can CPT 64493 be billed alone?
Yes. It is a primary code used for the first injected lumbar/sacral level in a session.

Do I need fluoroscopy or CT for this code?
Yes. One of these imaging methods must be used and documented.

How many times can I bill 64493?
It depends on the number of dates of service and payer rules. Medicare limits therapeutic sessions to 4 per region annually.

What’s the difference between 64493 and 64494?
64493 is for the first level. 64494 is an add-on code for the second level injected in the same region.

Do I use modifier 51 with 64493?
No. Modifier 51 is not used with 64493.

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