38 CFR Part 4 — 38 CFR § 4.124a

External popliteal nerve (common peroneal), paralysis — VA Diagnostic Code 8521

Peripheral nerves

Diagnostic code

8521

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38 CFR § 4.124a lists “External popliteal nerve (common peroneal)” and then Diagnostic Code 8521, “Paralysis of:” This block has one Rating column. It does not print Major and Minor. Complete is 40. Appendix B to Part 4 says “External popliteal nerve (common peroneal), paralysis.”

Reviewed 2026-10-05. Text checked against the eCFR versioner full-text XML for 2026-10-01 on 2026-10-05. Title 38 was up to date as of 2026-10-01 and last amended on 2026-08-27. The § 4.124a source note prints 29 FR 6718, May 22, 1964, as amended at 40 FR 42540, Sept. 15, 1975; 41 FR 11302, Mar. 18, 1976; 43 FR 45362, Oct. 2, 1978; 54 FR 4282, Jan. 30, 1989; 54 FR 49755, Dec. 1, 1989; 55 FR 154, Jan. 3, 1990; 56 FR 51653, Oct. 15, 1991; 57 FR 24364, June 9, 1992; 70 FR 75399, Dec. 20, 2005; 73 FR 54705, Sept. 23, 2008; 73 FR 69554, Nov. 19, 2008; 76 FR 78824, Dec. 20, 2011; 79 FR 2100, Jan. 13, 2014.

The rating criteria at each level

8521 Paralysis of the external popliteal nerve (common peroneal)

Rating %: 40

Criteria (verbatim). Complete; foot drop and slight droop of first phalanges of all toes, cannot dorsiflex the foot, extension (dorsal flexion) of proximal phalanges of toes lost; abduction of foot lost, adduction weakened; anesthesia covers entire dorsum of foot and toes

Rating %: —

Criteria (verbatim). Incomplete:

Rating %: 30

Criteria (verbatim). Severe

Rating %: 20

Criteria (verbatim). Moderate

Rating %: 10

Criteria (verbatim). Mild

Rating %	Criteria (verbatim)
40	Complete; foot drop and slight droop of first phalanges of all toes, cannot dorsiflex the foot, extension (dorsal flexion) of proximal phalanges of toes lost; abduction of foot lost, adduction weakened; anesthesia covers entire dorsum of foot and toes
—	Incomplete:
30	Severe
20	Moderate
10	Mild

8621 Neuritis. 8721 Neuralgia. Those two rows sit under DC 8521 and do not print a percentage.

The complete cell says “cannot,” “slight droop,” and “anesthesia covers entire dorsum of foot and toes.” It does not say the foot dangles and drops.

The Diseases of the Peripheral Nerves block says: The term “incomplete paralysis,” with this and other peripheral nerve injuries, indicates a degree of lost or impaired function substantially less than the type picture for complete paralysis given with each nerve, whether due to varied level of the nerve lesion or to partial regeneration. When the involvement is wholly sensory, the rating should be for the mild, or at most, the moderate degree. The ratings for the peripheral nerves are for unilateral involvement; when bilateral, combine with application of the bilateral factor. That sentence uses “varied level.” It says wholly sensory involvement should be mild, or at most moderate. 38 CFR § 4.26 is the bilateral factor the peripheral-nerve sentence names. The cranial-nerve sentence says to combine bilateral ratings without the bilateral factor. DC 8521 is in the peripheral-nerve block.

38 CFR § 4.123 caps neuritis characterized by the organic changes named in that section at severe incomplete paralysis, and otherwise at moderate, unless the sentence’s sciatic-nerve clause applies. 38 CFR § 4.124 caps neuralgia at moderate incomplete paralysis. On the DC 8521 scale, severe is 30 and moderate is 20. The complete-paralysis exception in § 4.124 is tic douloureux, or trifacial neuralgia. It is not this nerve. 38 CFR § 4.31 says that in every instance where the schedule does not provide a zero percent evaluation for a diagnostic code, a zero percent evaluation shall be assigned when the requirements for a compensable evaluation are not met. DC 8521’s lowest printed line is mild, 10. 38 CFR § 4.7 assigns the higher rating when the disability picture more nearly approximates the criteria required for that rating. Otherwise, the lower rating will be assigned. 38 CFR § 4.6 requires each element affecting the evidence to be studied so that decisions will be equitable and just.

DC 8520 is the sciatic nerve. Its complete line says the foot dangles and drops, no active movement possible of muscles below the knee, flexion of knee weakened or (very rarely) lost, at 80. That is not the DC 8521 complete cell. DC 8522 is the musculocutaneous nerve (superficial peroneal). Its complete line is “eversion of foot weakened,” at 30. The lower-extremity blocks, including DC 8521, do not use the Major and Minor columns that the upper-extremity blocks use.

Source: 38 CFR § 4.124a, Diagnostic Code 8521, eCFR full-text XML for 2026-10-01.

What the words mean in your records

One rating column

The external popliteal block prints 40, 30, 20, and 10. It does not print a second column. All radicular groups, DC 8513, is an upper-extremity block with Major and Minor. Those columns are not on DC 8521.

Slight droop, not foot dangles

DC 8521 says “foot drop and slight droop of first phalanges of all toes” and “cannot dorsiflex the foot.” DC 8520 says “the foot dangles and drops.” The public sciatic page is the radiculopathy guide.

Cannot

The DC 8521 complete cell spells “cannot” as one word. The radial-nerve complete cell elsewhere in the section spells “can not” as two words. This page keeps the spelling on this nerve.

Evidence that speaks to each level

The complete picture or the incomplete level

What the rater needs to see. Foot drop, dorsiflexion, toe extension, abduction and adduction, and sensation on the dorsum of the foot and toes, matched to the complete cell, or the severe, moderate, or mild incomplete line.

Where that usually lives. The peripheral-nerve examination and the treatment records that name the common peroneal nerve.

One side or both

What the rater needs to see. The peripheral-nerve sentence says the ratings are for unilateral involvement and that bilateral involvement is combined with the bilateral factor.

Where that usually lives. The examination of each side.

Level	What the rater needs to see	Where that usually lives
The complete picture or the incomplete level	Foot drop, dorsiflexion, toe extension, abduction and adduction, and sensation on the dorsum of the foot and toes, matched to the complete cell, or the severe, moderate, or mild incomplete line.	The peripheral-nerve examination and the treatment records that name the common peroneal nerve.
One side or both	The peripheral-nerve sentence says the ratings are for unilateral involvement and that bilateral involvement is combined with the bilateral factor.	The examination of each side.

VA’s public DBQ list, checked October 5, 2026, names “Peripheral Nerves” under Neurological. The file is Peripheral Nerves.

The exam form

DC 8521 prints four percentage lines. This page does not say the form replaces those lines.

Related codes and how they interact

Sciatic and superficial peroneal are the neighboring nerves.

DC 8520 is sciatic paralysis. DC 8522 is the musculocutaneous nerve, also called the superficial peroneal. DC 8521 is the external popliteal nerve, also called the common peroneal. Each complete cell uses different words.

Secondary conditions and presumptions

The 2026-10-01 text of 38 CFR § 3.309 does not contain “peroneal” or “popliteal.” Section 3.309(a) lists “Other organic diseases of the nervous system.” That family name is not assigned to DC 8521.

Short answers

What is the VA rating for common peroneal paralysis?

Diagnostic Code 8521 in 38 CFR § 4.124a prints 40 for complete, 30 for severe, 20 for moderate, and 10 for mild. Education only. VA decides on the evidence.

Does this nerve use major and minor ratings?

The external popliteal block does not. It has one Rating column. The Major and Minor columns are on the upper-extremity nerve blocks, including all radicular groups.

FAQ

What percentages does DC 8521 print?

Complete is 40. Severe incomplete is 30. Moderate is 20. Mild is 10. The block has one rating column. The complete cell describes foot drop, slight droop of the first phalanges of all toes, loss of dorsiflexion, lost abduction, weakened adduction, and anesthesia of the entire dorsum of the foot and toes. Education only.

Is foot drop under the sciatic nerve the same line?

No. DC 8520’s complete line says the foot dangles and drops, at 80. DC 8521’s complete line says foot drop and slight droop, at 40, and adds the dorsiflexion, abduction, adduction, and anesthesia clauses.

What is the cap for neuralgia of this nerve?

Section 4.124 caps neuralgia at moderate incomplete paralysis. On DC 8521, moderate is 20. The row 8721 prints “Neuralgia.” and no percentage. Section 4.123’s severe cap, 30 on this scale, is the neuritis rule when the organic changes that section names are present.

Next steps

Read the decision for DC 8521 or another lower-extremity nerve code, and which side it names.
The free worksheet is a place to write the code, the findings, and the records you already have. It does not file a claim or protect a filing date. An accredited representative is at find a VSO.
Other nerve codes are on the peripheral-nerve diagnostic-code index.

Education only. Not legal or medical advice. My Claim Packet is not a VA-accredited representative and does not file claims. VA decides every claim on its own evidence.

Other codes in this body system

Nearby catalog entries in Peripheral nerves, ordered by diagnostic code number. All Peripheral nerves codes

Also: DC code lookup (tools) lists the same index in a compact layout.

Source: 38 CFR Part 4, Diagnostic Code 8521 • va.gov

⚠️ Important Disclaimer

This page provides general educational information based on public VA regulations and VA.gov resources. It is not legal or medical advice, and My Claim Packet is not a VA-accredited representative. Any worksheets or draft documents produced by the tools must be reviewed for accuracy and are not filed with VA for you. Ratings and service connection are decided case-by-case from the individual record. Consult a VA-accredited VSO, claims agent, attorney, or qualified clinician for help with your situation, and verify current rules using the linked official source.