Answer: CPT-4 coding challenge: Coding nerve blocks 64400-64455

April 4, 2022 / By Jean Stoner

We recently presented a CPT-4 coding challenge with an example of a trigger finger release. We’ll repeat the example and provide the answer.

What CPT-4 code(s) should be assigned for this procedure?

1. Left ring finger trigger.
2. Left finger pain.

1. Left ring finger pulley release.
2. Peripheral nerve block for pain.

DESCRIPTION OF PROCEDURE: The patient was identified in preoperative holding area. Surgical site marked. Brought to the OR table, positioned supine. Tourniquet applied on proximal arm. A peripheral nerve block given consisting of 5 cc of 1% lidocaine with epinephrine and 0.25% Marcaine plain as a digital block for pain control and vasoconstriction. He was prepped and draped in usual sterile fashion. A time-out performed.

Preoperative antibiotics given. Extremity exsanguinated using Esmarch bandage. Tourniquet inflated to 220 mmHg. Transverse incision made in line with ring finger. Incision taken through subcutaneous tissues and palmar fascia. The digital bundles on both sides were identified and protected throughout the case. A1 pulley released under direct vision. Inflamed flexor tenosynovium excised sharply with scissors. The finger was taken through range of motion and found not to trigger. Hemostasis was obtained. Wound was washed out. Incision was closed with 4 – 0 nylon. Sterile dressing applied.


26055-F3 – Tendon sheath incision (e.g., for trigger finger)

You may wonder, “why isn’t the peripheral nerve block coded using 64450?” Nerve blocks are a necessary part of many surgical procedures for a total loss of feeling if needed for surgery and are often also used for post-operative pain relief, but if the block is not documented as being for post-operative pain management, then it is assumed to only be used for the surgery and therefore included in the surgical package and not coded separately. Providers must remember to be very clear to document that the block is for post-operative pain management, otherwise coders can’t assume that is the case and should not code the nerve block.

Here are some tips to help guide your coding for nerve blocks:

Operating providers

  • Do NOT report a 644xx nerve block code when performed by the same provider who performed the surgical procedure since blocks are considered part of the surgical package (Local infiltration, metacarpal/metatarsal/digital block or topical anesthesia) unless…
  • There is an exception to this if the block is done for post-surgical pain management, but please note that physician CMS Correct Coding Initiative (CCI) edits bundle many nerve block codes into surgical codes and do not allow for a modifier to bypass the edits (status 0 edits). Please note that for facilities, the edit can always be bypassed with a modifier when appropriate.

Example 1: Physician CCI edits for 26055 show 64450 as being a component of 26055, and it is allowed to be bypassed with a modifier if appropriate (1 status)
26055 – Tendon sheath incision (e.g., for trigger finger)
64450 – Injection(s), anesthetic agent(s) and/or steroid; other peripheral nerve or branch

Example 2: Physician CCI edits for 23412 show 64415 as being a component of 23412, and it is NOT allowed to be bypassed with a modifier (0 status)
23412 – Repair of ruptured musculotendinous cuff (e.g., rotator cuff) open; chronic
64415 – Injection(s), anesthetic agent(s) and/or steroid; brachial plexus

  • NOTE: Not all “peripheral nerve blocks” are 64450 (other peripheral nerve)
    • Femoral nerve block = 64447
    • Sciatic nerve block = 64445
    • IPACK block (Infiltration between the popliteal artery and capsule of the knee) = 64999 (common nerve block used for knee surgery). See CPT Assistant June 2020, page 14, for an FAQ on coding IPACK blocks.


    • When general anesthesia is administered and these injections are performed to provide postoperative analgesia, they are separate and distinct services and are reported in addition to the anesthesia code regardless of whether the block procedure (insertion of catheter; injection of narcotic or local anesthetic agent) occurs preoperatively or postoperatively.
    • If, on the other hand, the block procedure is used primarily for the anesthesia itself, the service should be reported using the anesthesia code alone. In a combined epidural/general anesthetic, the block cannot be reported separately.


  • If the operating provider performed the nerve block to provide loss of feeling for surgery, do not code the nerve block, it is bundled into the surgical CPT code.
  • If the operating provider performed the nerve block for post-operative pain management, code the nerve block with the surgical CPT code, but there may be CMS CCI edits in place and for some blocks you may or may not be able to bypass the CCI edit with a modifier.
  • If the anesthesiologist provided the nerve block, code the ASA Anesthesia CPT code, unless the block is for post-operative pain management in which case both the nerve block and the ASA anesthesia CPT can be coded.

Jean Stoner, CPC, product owner for computer-assisted coding (CAC) content for outpatient and professional services for 3M Health Information Systems.