Epidural steroid injections (ESIs) are among the most frequent procedures in pain management, spine and physiatry practices, and among the most audited. As a result, epidural steroid injection billing leaves little room for error. A wrong approach code, a missing imaging note or a fifth session in a year can turn a routine injection into a denial or a Recovery Auditor finding.
This guide walks through epidural steroid injection billing step by step: choosing the right CPT code, meeting Medicare LCD criteria, tracking session limits and documenting repeat injections so claims pay the first time.
ESI CPT Codes by Approach
The approach and spinal region decide the code. Interlaminar and caudal injections use the 62320–62323 family, while transforaminal injections use 64479–64484.
| Approach and region | CPT code | Key point |
|---|---|---|
| Interlaminar or caudal, cervical/thoracic | 62321 | Imaging included |
| Interlaminar or caudal, lumbar/sacral | 62323 | Imaging included |
| Transforaminal, cervical/thoracic | 64479, +64480 per added level | Imaging included |
| Transforaminal, lumbar/sacral | 64483, +64484 per added level | Imaging included |
Report interlaminar and caudal codes once per session, whatever the number of levels the medication reaches. In contrast, transforaminal codes are per level, with the add-on code for the second level. Catheter-based infusions (62324–62327) are a separate family and rarely part of routine epidural steroid injection billing. For a broader view of pain management code sets, see our guide to pain management CPT, ICD-10 & HCPCS codes.
Imaging Rules That Decide the Code
Medicare ESI policies require fluoroscopic or CT guidance, which is why imaging drives code choice:
- Use 62321 or 62323, not 62320 or 62322. The no-imaging codes are generally not covered under the Medicare ESI LCDs.
- Do not add 77003 or 77012. That is because fluoroscopic and CT guidance are already part of the ESI codes.
- Ultrasound does not qualify. It is not accepted guidance for ESIs under these policies.
- Keep the images. Also, payers expect saved images or a clear note of the views obtained and contrast spread.
If imaging was not used, bill the no-imaging code honestly and expect a coverage denial rather than upcoding to 62321 or 62323.
Medicare ESI Coverage Criteria
Every A/B MAC now applies an ESI LCD with largely the same criteria, such as Novitas L36920 and CGS L39015, as summarized by ASIPP. A covered ESI generally needs:
- Radicular pain or spinal stenosis symptoms, not axial back pain alone
- At least 4 weeks of pain with failed or intolerable conservative care, such as therapy or medication
- A baseline pain or function score, repeated at each follow-up
- One spinal region per session, with fluoroscopic or CT guidance
Pair the procedure with a supported diagnosis, such as lumbar radiculopathy (M54.16) or spinal stenosis with neurogenic claudication (M48.062). Generic low back pain codes rarely support an ESI on their own; our guide to low back pain ICD-10 codes explains the difference.
Session Limits: Four per Region per Year
Medicare counts sessions, not injections. A session is every epidural injection in one spinal region on one date, and the LCDs allow no more than four sessions per region in a rolling 12 months.
| Date | Service | Lumbar sessions counted |
|---|---|---|
| Jan 10 | 64483 + 64484, left L4-5 and L5-S1 | 1 |
| Feb 14 | 62323, L5-S1 interlaminar | 2 |
| Jun 20 | 64483-50, bilateral L5-S1 | 3 |
| Oct 3 | 64483, right L4-5 | 4 |
| Dec 15 | Any lumbar ESI | Not covered until Jan 10 drops out |
Cervical/thoracic and lumbar/sacral are counted separately, so a cervical ESI in December would not be blocked by this lumbar history. Therefore, track the rolling window in your scheduling or billing system, not by calendar year.
Bilateral and Multi-Level Injections
In epidural steroid injection billing, transforaminal injections are where most unit and modifier errors happen. Medicare billing guidance, such as the Noridian ESI billing article, allows:
- Up to two levels per session, unilateral or bilateral. Bill the primary level and one add-on (64480 or 64484).
- Modifier 50 for both sides at the same level, such as 64483-50. Do not report two lines with RT and LT for Medicare.
- One interlaminar or caudal injection per session. However, Medicare does not pay a second interlaminar level on the same day separately.
Commercial payers may require RT/LT lines instead of modifier 50, so set each payer format in your billing system before claims go out.
Documenting a Repeat Injection
Medicare Recovery Auditors check lumbar transforaminal ESIs for medical necessity and documentation, so the follow-up note matters as much as the procedure note. To support another session, document:
- Relief from the prior injection: at least 50% pain relief or meaningful functional improvement lasting at least 3 months
- Pain and function scores before and after each injection, using the same scale
- Continued radicular symptoms that justify another injection
- Dates of every prior session in that region, to show the four-session limit is not exceeded
If the first injection gives little relief, the LCDs allow a limited second attempt, such as a different approach or level, only with documented reasoning. Weak conservative care notes are another common gap; our guide to failed conservative treatment documentation shows what reviewers expect.
Epidural Steroid Injection Billing Denials and Fixes
Most epidural steroid injection billing denials trace back to a short list of preventable gaps.
| Denial | Likely cause | Fix |
|---|---|---|
| Not medically necessary | Axial pain only, or under 4 weeks of conservative care | Document radicular findings and conservative care dates |
| Frequency exceeded | Fifth session in a region within 12 months | Track sessions on a rolling basis before scheduling |
| Non-covered code | 62320 or 62322 billed without imaging | Use imaging and bill 62321 or 62323 |
| Units or level error | Third transforaminal level or extra add-on | Limit to two levels per session |
| Bilateral format | RT/LT lines sent to Medicare | Use modifier 50 on one line |
| Repeat not supported | No relief percentage or duration recorded | Record pain scores and relief at each follow-up |
Paid claims deserve review too. One pain practice corrected a 38% underpayment on nerve block and epidural claims, as shown in our epidural underpayment case study.
Clean ESI Claims Start Before the Needle
Epidural steroid injection billing comes down to a few decisions made before and after the procedure: the right approach code with imaging, a covered diagnosis, a session count that stays within four per region, and follow-up notes that prove relief. When those pieces are in place, ESI claims stand up to both payer edits and audits.
If ESI denials or audit risk are slowing your collections, MBW RCM can help. Through our pain management billing services, we track session limits, check documentation before submission and code each injection to the payer policy.
Epidural Steroid Injection Billing FAQs
What is the difference between 62321 and 62323?
Both are interlaminar or caudal epidural injections with imaging. 62321 is for the cervical or thoracic spine, while 62323 is for the lumbar or sacral spine.
Can 77003 be billed with an epidural steroid injection?
No, because fluoroscopic guidance is already part of 62321, 62323 and the transforaminal codes 64479-64484.
How many epidural steroid injections does Medicare allow per year?
Up to four sessions per spinal region in a rolling 12 months, with documented relief supporting each repeat.
How many levels can be billed for a transforaminal ESI?
Up to two levels per session, unilateral or bilateral: the primary code plus one add-on (64480 or 64484).
How do you bill a bilateral transforaminal epidural?
For Medicare, report one line with modifier 50, such as 64483-50. However, some commercial payers require separate RT and LT lines.
What documentation supports a repeat ESI?
At least 50% relief or functional improvement for 3 months or more, pain scores before and after each injection, and dates of prior sessions in that region.