Glossary · Clinical
Nerve block
A nerve block is an injection of local anesthetic—sometimes combined with a corticosteroid—into or around a specific nerve or nerve plexus to interrupt pain signaling. In orthopedics, it serves both as a diagnostic tool to confirm a pain generator and as a therapeutic intervention for acute or chronic musculoskeletal pain.
Verified May 8, 2026 · 8 sources ↓
Definition
Source · Editorial summary grounded in 8 cited references ↓
A nerve block delivers anesthetic agent, steroid, or both to a targeted nerve or nerve plexus to temporarily or semi-permanently disrupt nociceptive transmission. The injection site determines the CPT code: anatomy-specific codes govern everything from the trigeminal nerve (64400) to the femoral nerve (64447) to the brachial plexus (64415). Imaging guidance—ultrasound (76942) or fluoroscopy (77002)—is frequently used to improve needle placement accuracy and is billed separately unless the applicable CPT descriptor explicitly bundles it (e.g., 64493 for paravertebral facet blocks).
In orthopedic practice, nerve blocks fill two distinct roles. Diagnostically, a positive response to a selective nerve block helps isolate the anatomic source of pain before committing to surgery. Therapeutically, they provide targeted analgesia for conditions ranging from acute fracture pain to chronic neuropathy, and are a cornerstone of multimodal postoperative pain protocols designed to reduce opioid consumption. Continuous infusion techniques—reported with add-on codes such as +64416 for brachial plexus—extend analgesia beyond a single-injection window.
Medicare coverage is indication-dependent and anatomy-dependent. CMS LCD L35456 explicitly excludes nerve blocks for metabolic peripheral neuropathy, citing insufficient evidence. Blocks performed as the sole or adjunct regional anesthetic for an operative procedure (e.g., wound debridement) follow different billing rules than those performed for standalone chronic pain management. Payer policies vary materially, so diagnosis linkage via ICD-10-CM codes is not optional—it is the primary mechanism through which medical necessity is established on the claim.
Why it matters
Selecting the wrong CPT code—for example, using the catch-all 64450 (other peripheral nerve) when anatomy-specific 64415 (brachial plexus) is documented—directly reduces reimbursement and flags the claim for NCCI edit review. Conversely, billing imaging guidance separately when it is bundled into the procedure code (or failing to bill it at all when it is legitimately unbundled) creates either a denial or an underpayment. CMS article A57452 requires that the specific nerve targeted, the agent injected, the approach, and the clinical rationale all appear in the medical record; missing any one of those elements gives a MAC auditor grounds for recoupment.
Common mistakes
Where people most often go wrong with this concept.
Source · Editorial brief grounded in cited references ↓
- Using CPT 64450 (other peripheral nerve) when the operative report identifies a named nerve or plexus that has its own anatomy-specific code (e.g., 64415 for brachial plexus, 64447 for femoral nerve).
- Billing fluoroscopy (77002) or ultrasound (76942) separately when the CPT descriptor for the block already bundles imaging guidance, triggering an NCCI edit denial.
- Failing to append modifier -50 for bilateral blocks or using two line items with modifier -LT/-RT on a professional claim instead of the correct bilateral reporting method for the place of service.
- Reporting a continuous-infusion add-on code (+64416) without first billing the corresponding base injection code, making the add-on unprocessable as a standalone charge.
- Linking the claim to an ICD-10-CM code that CMS explicitly excludes—such as metabolic peripheral neuropathy diagnoses covered under LCD L35456—resulting in automatic non-coverage denial under Medicare Part A and B.
- Omitting modifier -59 or -XU when an anesthesia practitioner performs a peripheral nerve block for postoperative pain management after the primary anesthesia care period ends, causing the block to be bundled into and denied against the anesthesia claim.
- Defaulting to a 0-day global period assumption without verifying payer-specific policies; some commercial payers apply a 10-day global to certain block codes, restricting separately billable follow-up on those dates.
Related codes
Codes commonly involved when this concept appears in practice.
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 8 cited references ↓
01Why can't I always use CPT 64450 for a peripheral nerve block to keep coding simple?
02Is imaging guidance always billed separately from the nerve block code?
03Does Medicare cover nerve blocks for all types of peripheral neuropathy?
04How do I report a nerve block performed by the anesthesia team specifically for postoperative pain after the main anesthesia is complete?
05What is a continuous peripheral nerve block and how is it coded differently from a single injection?
06What changed in CPT 2025 that orthopedic coders should know about nerve blocks?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
- 01cms.govhttps://www.cms.gov/medicare-coverage-database/view/article.aspx?articleid=57452
- 02cms.govhttps://www.cms.gov/medicare-coverage-database/view/article.aspx?articleId=56034
- 03cms.govhttps://www.cms.gov/medicare-coverage-database/view/lcd.aspx?lcdId=40266
- 04cms.govhttps://www.cms.gov/medicare-coverage-database/view/article.aspx?articleId=60321&ver=2
- 05aapc.comhttps://www.aapc.com/codes/coding-newsletters/my-orthopedic-coding-alert/orthopedic-coding-look-to-new-plane-block-code-for-2025-178782-article
- 06gohealthcarellc.comhttps://www.gohealthcarellc.com/blog/learn-billing-and-coding-peripheral-nerve-block-cpt-64450-64405-64420-64447-64418
- 07AMA CPT Guidelines (current edition)
- 08CMS NCCI Policy Manual (2021 and current)
Mira AI Scribe
When documenting a nerve block encounter for Mira's coding layer, explicitly state: (1) the exact nerve or plexus targeted by anatomic name (e.g., 'left femoral nerve' rather than 'lower extremity nerve'); (2) the agent(s) injected and their concentrations; (3) whether the technique was single injection or continuous catheter infusion; (4) whether imaging guidance was used, the modality (ultrasound or fluoroscopy), and that a permanent image was stored—this last point is required to support a separate imaging guidance code; (5) the clinical indication tied to a specific, covered ICD-10-CM diagnosis (avoid vague terms like 'pain' that map to non-specific codes); and (6) laterality. If the block is performed post-operatively for pain management after the anesthesia care period has ended, document that distinction explicitly so modifier -59 or -XU can be applied correctly. For bilateral procedures, note both sides clearly so modifier -50 (or -LT/-RT in ASC facility settings) is applied at the right line-item level. Mira will use these data points to select the anatomy-specific CPT code, determine whether imaging guidance is separately billable under NCCI rules, and confirm ICD-10 linkage against the applicable CMS LCD and MAC policy for the patient's jurisdiction.
See Mira's approachRelated terms
A Local Coverage Determination (LCD) is a regional Medicare policy issued by a Medicare Administrative Contractor (MAC) that defines when a specific service, procedure, or supply is considered reasonable and medically necessary within that contractor's jurisdiction.
Medical necessity is the standard requiring that a service or item be reasonable and appropriate for diagnosing or treating a patient's condition according to accepted clinical practice. Payers—including Medicare—use this standard to determine whether a claim will be covered and paid.