Muscle Injuries Rating Guide

Muscle injuries, often from shrapnel, gunshot, blast, or surgery, and sometimes from a repeated strain rather than a wound, are rated differently from joints. Instead of measuring degrees of motion, 38 CFR § 4.73 sorts the body's muscles into 23 muscle groups and scores each injury from slight to severe, based on the damage the wound or strain left behind. This guide walks the whole path: how service connection works, direct and secondary pathways, how the muscle group and severity grade are chosen, the evidence that wins, why these claims get denied, a checklist before you file, what the claims process looks like step by step, how to read your decision letter, and what to do whether you win or you're denied.

Last updated: July 2026 · Educational use only. Not legal advice. Verify current rules at VA.gov or eCFR.

Overview

Muscle injuries covered here include both wounds, such as gunshot and shrapnel wounds, and muscle strains, and they are rated under 38 CFR § 4.73, Diagnostic Codes 5301 through 5323 (this guide's meta also spans the broader 5301-5329 range some references use for the muscle groups). A muscle-injury claim really involves two separate fights: whether the muscle condition connects to your service at all, and, once it is connected, how severe VA rates it under 38 CFR § 4.56. In practice, most veterans who bring a muscle-injury issue to an appeal have already won service connection, the real dispute is the rating percentage, a separate rating for a second muscle group, the effective date, or occasionally a clear-and-unmistakable-error motion. Knowing which fight you're actually in tells you where to focus your evidence.

Board decisions are not binding on other cases and do not set VA policy. They show patterns in how the rules have been applied, not a guarantee about any individual claim. Your result depends on your own facts and the current regulations.

Muscle Groups and How Severity Is Graded

A muscle injury is not rated on range of motion the way a joint is. It is rated on which muscle group was hit and how badly it was damaged. A handful of shared rules decide both, and they apply the same way to a thigh wound, a shoulder wound, and a forearm wound.

1. Every injury is assigned to one of 23 muscle groups

The VA divides the body's muscles into 23 muscle groups, numbered with Roman numerals I through XXIII, organized by body region and by the movement the muscles perform. The group your injury falls into determines which diagnostic code and which rating scale applies. Muscle codes run from DC 5301 to DC 5329.

2. The injury is graded slight, moderate, moderately severe, or severe (38 CFR 4.56)

Within a group, the wound is graded on a four-step scale: slight, moderate, moderately severe, or severe. The grade comes from the "cardinal signs and symptoms of muscle disability": loss of power, weakness, a lowered threshold of fatigue, fatigue-pain, impairment of coordination, and uncertainty of movement. The more of these signs the injury produces, and the more strongly, the higher the grade.

3. The wound history is part of the grade

The severity grade is not read from strength alone. The history of the wound counts too. A through-and-through or deep penetrating wound, debridement (surgical cleaning of the wound), a prolonged infection or hospitalization, retained metal fragments visible on x-ray, loss of muscle tissue (substance), and deep, ragged, or adherent scarring all point toward the higher grades. A small, clean, well-healed wound points toward the lower grades. A through-and-through wound is graded at least moderate for each muscle group it passed through, regardless of how mild it otherwise looks.

4. Muscle groups in the same limb do not simply add (38 CFR 4.55)

When more than one muscle group in the same limb is injured, the ratings do not just add together. 38 CFR § 4.55 sets specific rules for combining them, and it also ties muscle injuries to the joints they move: an injury to a muscle group that moves a joint is considered alongside any limitation of motion of that same joint, so the two are weighed together rather than counted as if they were unrelated. Muscle groups in different body regions, by contrast, can each earn their own separate rating. Either way, rating the same symptoms twice under two different codes (pyramiding) is not allowed under 38 CFR § 4.14.

Muscle groups and joints often overlap. Because a muscle's whole job is to move a joint, a serious muscle wound and a limited, painful joint frequently show up in the same claim. The muscle-group rating (4.73) and the limitation-of-motion rating (4.71a) measure different things, so they are weighed together under 4.55 rather than one simply canceling the other. See the musculoskeletal guide for the motion side.

Find the Guide for Your Condition

The muscle-group system has no single per-condition guide, because each of the 23 groups sits in a different part of the body. The closest related pages are the joint side the muscles move and the scar left by the wound:

AreaGuideDC codes
Joints the muscles moveMusculoskeletal Guide5301-5329 related
Scars from the woundScars & Burns Guide7800-7805

Muscle codes run from 5301 to 5329. For any specific muscle group, open its condition lookup page for the exact rating levels and Board data.

How Service Connection Works, At a High Level

Before getting into the specific pathways below, it helps to understand the three things every muscle-injury claim ultimately has to show. This is the same basic test that applies to any VA disability claim, just applied to this condition.

  1. A current diagnosis. You need a muscle condition, diagnosed now. With no current diagnosis actually documented in the record, there is no valid claim, even if a wound or strain clearly happened in service.
  2. An in-service cause. An injury or event during service, such as a gunshot or shrapnel wound, a fall, a blast, surgery, or a repeated strain. Both wounds and strains count under 38 CFR § 3.303.
  3. A medical nexus. A medical opinion connecting your current muscle condition to that in-service event, or to a service-connected condition behind it, and explaining the reasoning, not just stating a conclusion. An opinion that explains its reasoning is given more weight than a bare conclusion.
You don't always have to prove all three yourself. VA sometimes concedes the diagnosis, and occasionally the in-service event too, leaving only the medical nexus genuinely in dispute. Knowing which of the three elements is actually contested in your case tells you where to focus your evidence. See the Service Connection Guide for how this test works generally.

What VA Looks For: Tests, Records, and Diagnostic Codes

Whether you are filing directly, secondary to another condition, or fighting over the severity grade, the record VA actually reviews centers on a small set of documents and data points.

  • The wound or strain history: service treatment and hospital records describing the type of wound, any surgery, debridement, whether the wound was through-and-through, a prolonged infection, and how long treatment or hospitalization lasted. This history is what sets the severity grade under 4.56.
  • Strength testing and the cardinal signs: documented findings of loss of power, weakness, a lowered threshold of fatigue, fatigue-pain, impairment of coordination, and uncertainty of movement.
  • Imaging: X-ray, CT, or MRI showing retained metal fragments still in the muscle, or lost muscle tissue (substance) and deep fascia damage.
  • The resulting scar: its size, and whether it is deep, tender, ragged, or adherent, so it can be documented and rated separately under the scar codes.
  • The diagnostic codes and muscle group involved: DC 5301 through 5329 by muscle group (I through XXIII), plus, where relevant, the joint code under 4.71a that the muscle moves, or a nerve code if the same wound also struck a nerve.
  • The matching DBQ: the Disability Benefits Questionnaire specific to muscle injuries, which prompts the examiner to capture the wound history and the cardinal signs, discussed in more detail later in this guide.

Service Connection Pathways: Direct and Secondary

Muscle injuries are not a VA presumptive condition category on their own. Service connection must be established through one of the following pathways.

Direct Service Connection

A veteran demonstrates that the muscle injury, whether a wound or a strain, began during or was caused by active military service. Wounds and strains both count. Supporting evidence includes service treatment and hospital records describing the injury, and a medical nexus opinion linking the current muscle condition to that in-service event. This is the most straightforward pathway when the wound or strain is documented in service records. See our Service Connection Guide.

Secondary via Altered Gait or Overuse Compensation

A service-connected condition in one limb, such as a knee, ankle, hip, or back disability, can change how a veteran walks or moves to avoid pain. Over time, that altered gait or compensating movement pattern can overload and strain muscle groups in the same limb, the opposite limb, or the back that were never directly injured. This is a recognized biomechanical-compensation theory of secondary service connection: the original service-connected condition is the cause, and the new muscle strain is the effect. A nexus opinion should describe the specific compensating movement and how it plausibly overloaded the muscle group at issue.

Secondary via Scar Tissue or Adhesions

Scar tissue or adhesions from an original wound, surgery, or debridement to one muscle group can restrict movement or place abnormal strain on an adjoining muscle group as it works around the restriction. Where a nexus opinion documents that mechanism, connecting the adjacent muscle group's condition back to the original, already service-connected wound, this can support a secondary claim distinct from the original muscle rating itself.

Secondary Service Connection Generally (38 CFR § 3.310)

Beyond the two pathways above, a veteran can demonstrate that a muscle condition was caused or chronically aggravated by any already service-connected condition, not only a limb or scar. See our Secondary Service Connection Guide.

Worsening counts too, not just causing. If a service-connected condition made an existing muscle condition worse, even by a modest amount, that can be enough under the aggravation prong of 38 CFR § 3.310(b). A medical opinion addressing secondary connection should speak to both the causation question and the aggravation question; an opinion that only addresses one is incomplete.

Service Connection by Aggravation

When a veteran had a documented pre-service muscle condition that was significantly worsened beyond its natural progression by military service, aggravation-based service connection under 38 CFR § 3.306 is available.

Reopening With New Service Records

If official service records surface later that were not part of the file when an earlier decision was made, VA can reconsider that decision as if it had never been finally decided, rather than requiring an ordinary new-and-material-evidence reopening. See 38 CFR § 3.156(c).

How VA Grades Severity Under 38 CFR 4.56

Each muscle group's diagnostic code (DC 5301 through 5329) carries its own percentage table, and the exact percentage at each grade varies by group and by limb (dominant vs. non-dominant). What is constant across all 23 groups is the four-step severity scale itself, defined in 38 CFR § 4.56. Check your specific muscle group's own DC page for the percentage that applies at each grade.

SevereExtensive, disabling loss of muscle function

Signs include prolonged hospitalization for a wound of this severity, x-ray evidence of scattered metal fragments, ragged or adherent scars indicating wide damage and loss of deep fascia, and measured loss of strength or muscle substance on testing, together with a marked degree of the cardinal signs.

Moderately SevereSignificant, objectively documented impairment

A through-and-through or deep penetrating wound of a longer-acting type, hospitalization, and a moderate number of the cardinal signs, consistently and objectively shown on repeated examinations, without reaching the extensive tissue loss of a severe rating.

ModerateThrough-and-through or deep wound with some loss of function

A through-and-through or deep penetrating wound counts as at least moderate for every muscle group it passed through, regardless of how mild the residual symptoms otherwise look. Some of the cardinal signs are present, but less consistently or less severely than moderately severe.

SlightMinimal, well-healed injury

A simple wound or strain with a minimal scar, no significant limitation of function, and none or almost none of the cardinal signs on examination.

Separate ratings for separate muscle groups. Muscle groups in different body regions can each get their own rating under 38 CFR § 4.55. If more than one group was injured, for example by the same gunshot wound, ask VA to consider a separate rating for each affected group rather than one combined figure, and watch for a wrongly combined rating for a muscle and an adjoining joint that should have been kept as two distinct evaluations.

Evidence for a Muscle Injury Claim

Service treatment, hospital, and wound-care records: describing the type of wound or strain, any surgery, debridement, a prolonged infection, and how long treatment or hospitalization lasted. Newly found official service records can even reopen an old rating as if it had never been decided.

Strength testing: documenting the weakness and the lowered threshold of fatigue the severity grade depends on.

Imaging (X-ray, CT, or MRI) showing lost muscle tissue, deep fascia damage, or retained metal fragments still in the muscle. This is often the difference between a mid-tier and a higher severity grade.

Documentation of the resulting scar: its size, and whether it is deep, tender, ragged, or adherent, so it can be rated separately under the scar codes.

A nexus opinion that explains its reasoning: for direct or secondary claims, a medical opinion from a treating provider or qualified clinician connecting the current muscle condition to service or to a service-connected condition, and explaining how, not just stating a conclusion. An opinion that cites the veteran's specific history and applies medical literature to those facts carries more weight than a bare conclusion, and outweighs a VA opinion that only points to gaps in treatment.

A detailed record of your cardinal symptoms: loss of power, weakness, a lowered threshold of fatigue, fatigue-pain, impairment of coordination, and uncertainty of movement, described specifically and tied to how they limit work and daily activities. A later exam that documents more of these signs can raise the severity grade.

The matching DBQ for the muscle injury, which prompts the examiner to capture the wound history and the cardinal signs. See the DBQ Guide.

Lay statements: your own first-person description of symptoms and how they limit function is useful supporting evidence, but a complex medical cause generally still needs a doctor's opinion behind it; a lay account alone typically does not outweigh a specialist's contrary opinion on causation. See our Buddy & Lay Statements Guide. (Jandreau v. Nicholson, 492 F.3d 1372 (Fed. Cir. 2007).) See our Nexus Letters Guide.

Why These Claims Get Denied

Beyond the general "no nexus" and "no diagnosis" reasons, a few specific denial patterns show up often enough in published Board decisions to call out on their own.

  • A diagnosis tied only to a cause unrelated to service. A confirmed muscle or nerve condition, connected only to years of civilian work or another cause after discharge rather than to anything documented in service, does not establish service connection by itself.
  • No proof of a current condition at all. With no current diagnosis actually shown in the record, there is no valid claim, even where other conditions in the same file are well documented (Brammer v. Derwinski, 3 Vet. App. 223 (1992)).
  • The veteran's own belief about the cause, without a doctor's opinion behind it. VA treats the cause of a complex muscle or nerve condition as a medical question a non-doctor generally cannot answer alone. A veteran's personal opinion that service caused the condition, without a supporting medical nexus, does not carry the claim (Jandreau v. Nicholson).
  • A long, unexplained gap between service and the first record of the condition. Decades between discharge and the first documented complaint or diagnosis can be weighed as evidence against an in-service onset.
  • Expecting a higher severity grade without objective findings. Moving from moderate to moderately severe or severe usually needs objective proof, prolonged hospitalization, loss of muscle substance or deep fascia, or measured loss of strength, not just reported pain. Normal strength testing with no atrophy and no prolonged infection tends to keep a claim at a lower grade.
  • A medical opinion built on a wrong fact. An opinion that overlooks or misstates an actual period of service, an event, or a record in the file is treated as unreliable and given little weight (Reonal v. Brown, 5 Vet. App. 458 (1993)).

Common Mistakes

  • Assuming a muscle injury and a joint limitation cannot both be rated. They measure different things and often both apply. A muscle-group rating and a limitation-of-motion rating are weighed together under 4.55, not simply canceled.
  • Not documenting the cardinal signs. Loss of power, weakness, fatigue, fatigue-pain, and impaired coordination are what set the severity grade. If the exam does not record them, the grade drops.
  • Overlooking retained fragments and scars. Metal fragments left in the muscle and the scar the wound left are separate parts of the rating, not just background detail.
  • Not describing the original wound in enough detail. A through-and-through wound, debridement, or a long infection all justify a higher grade, but only if the record actually describes them.
  • Treating a clear-and-unmistakable-error (CUE) motion as an easy fix. A CUE motion requires an error that is undebatable and would have changed the outcome, a very high bar under 38 CFR § 3.105. Motions to backdate an old muscle-injury grant by decades often fail because the old records do not clearly show a muscle disability at that earlier time.
  • Missing the one-year window to appeal. Effective-date and rating-percentage disputes have a one-year deadline to appeal. Missing it closes off most of the ordinary paths to correct the decision.

Do's and Don'ts

A condensed version of everything above, in the order it actually matters when you sit down to build your file.

Do
  • Get examined and make sure a current diagnosis of your muscle condition is actually in the file.
  • Gather your service treatment and hospital or wound-care records, including any debridement, infection, or hospitalization history.
  • Get a nexus opinion that explains its reasoning and cites your specific medical history, not a bare conclusion.
  • Write down every cardinal sign, weakness, fatigue-pain, loss of power, lowered fatigue threshold, coordination trouble, and how each limits your work and daily activities.
  • Ask VA to rate each injured muscle group separately when more than one is hurt.
  • Read your VA exam reports and flag any wrong dates or missed events.
  • Seek treatment and file as early as you can.
  • Appeal within one year if you disagree with the rating percentage or the effective date.
Don't
  • Don't assume a diagnosis alone wins the claim, you still need the connection to service.
  • Don't file without a current diagnosis actually documented in the record.
  • Don't rely only on your own opinion about what caused a complex muscle condition.
  • Don't expect a jump to a higher severity grade without objective findings like measured strength loss, muscle-substance loss, or hospitalization.
  • Don't wait years without treatment or filing, an unexplained gap can be weighed against you.
  • Don't count on a CUE motion to fix an old effective date, the bar is very high and it often fails on older, incomplete records.
  • Don't miss the one-year deadline to appeal a rating or effective-date decision.

Common Secondary Conditions

A muscle wound rarely affects only the muscle. Because the muscle moves a joint and sits next to nerves, skin, and the opposite limb, one injury often opens the door to several related claims:

  • Limitation of motion of the joint the muscle moves. A damaged muscle can no longer move its joint through the full range, so the joint's lost motion is weighed alongside the muscle rating.
  • The opposite limb. Overcompensating for a weak or painful muscle overloads the other side over time, the way a weak leg makes you lean on the good one.
  • Scars from the original wound. The scar the wound left is rated separately under the scar codes, on top of the muscle rating. See the scars and burns guide.
  • Nerve damage. If the same wound also struck a nerve, that nerve injury is rated separately under the nerve codes. See the neurological guide.

For how a service-connected condition supports a related claim, see secondary conditions.

A note on the data gap here. Because the 23 muscle groups spread published Board decisions across many separate diagnostic codes (5301 through 5329), none of them currently has enough coded decisions in our data to support a reliable grant-rate widget on this page. Check the specific muscle group's own condition lookup page for its own numbers if one is available.

Quick Checklist Before You File

Bring these together before you submit anything.

  • A current diagnosis of your muscle condition from a doctor.
  • Your service treatment records, including any hospital or wound-care records.
  • A medical nexus opinion that explains its reasoning and cites your history.
  • A written record of your cardinal symptoms: weakness, fatigue-pain, loss of power, and how they limit work and daily life.
  • If more than one muscle group is injured, a request that VA consider a separate rating for each affected group.
  • Your VA exam reports, reviewed for any wrong dates or missed events.
  • A plan to appeal within one year if you disagree with the rating percentage or the effective date.

For the mechanics of actually submitting the claim, see the Standard Claim Guide and the Fully Developed Claim Guide (filing with all your evidence up front can speed up the decision).

The Claims Process, Step by Step

Once you file, your claim moves through a series of hand-offs. Understanding who does what helps you know who to contact, and what to expect, at each stage.

  1. You file the claim. Directly with VA, through VA.gov, or with the help of an accredited representative.
  2. VA acknowledges the claim and assigns it for development. A Veteran Service Representative (VSR) is assigned to gather your service treatment and hospital records, VA and private medical records, and any other evidence needed.
  3. The VSR orders a Compensation & Pension (C&P) exam if one is needed. Most muscle-injury claims do, especially where the severity grade or a secondary nexus opinion is at issue.
  4. The C&P exam is conducted. By a VA clinician or a contracted examiner, who completes a muscle-injury Disability Benefits Questionnaire (DBQ) documenting the diagnosis, the cardinal signs, the wound history, and, where relevant, a nexus opinion.
  5. The file goes to a Rating Veteran Service Representative (RVSR), the "rater." The rater reviews the complete file, including the exam results, and decides the muscle group, the severity grade, and the percentage.
  6. A senior reviewer may review the decision before it's finalized, depending on the complexity of the claim.
  7. VA issues the decision letter. This states whether the claim is granted or denied, the rating percentage if granted, and the reasons behind the decision.
  8. If you disagree, you choose an appeal lane. Higher-Level Review, Supplemental Claim, or a Board appeal, covered later in this guide.

Who's who: VSO vs. VSR vs. Rater vs. C&P Examiner

Your VSO

An accredited representative from a veterans service organization, or an accredited attorney or claims agent. Not a VA employee. Helps you prepare, gather evidence, and file, and can represent you through an appeal. Has no authority to decide your claim.

VSR (Veteran Service Representative)

VA staff who "develops" your claim: requests records, schedules the C&P exam, and assembles the file. Does not decide the rating.

Rater (RVSR)

VA staff who reviews the completed file and makes the actual decision, service connection or denial, the muscle group and severity grade, and the percentage. This is the person whose judgment the decision letter reflects.

C&P Examiner

A VA clinician or a contracted medical examiner who conducts the exam and completes the DBQ. Documents findings and, where asked, a nexus opinion. Does not decide the claim.

For the full walkthrough of every stage with more detail, see Inside Your Claim and Claim Stages.

DBQs and Your C&P Exam

A Disability Benefits Questionnaire (DBQ) is the standardized form an examiner completes for your condition, it structures the exam findings into the specific data points VA's rating schedule requires (for a muscle injury, that includes the wound history, the cardinal signs, strength testing, and scar documentation). See the DBQ Guide for how these forms work, including whether a private DBQ completed by your own doctor can be submitted instead of relying solely on a VA exam.

Before your C&P exam, bring a clear, specific account of your symptoms, focus on your worst days and how the condition affects daily function and work, not just how you feel on an average day. Be consistent with what's already in your medical records and prior statements. For a full walkthrough of what to expect and how to prepare, see the C&P Exam Prep Guide.

Reading Your Decision Letter, and What to Do If Denied

Your decision letter has two parts: a narrative section explaining the reasoning (often called "reasons and bases"), and a codesheet showing the actual rating percentage, the effective date, and the diagnostic code used. See the Reading Your Decision Letter Guide for how to find and interpret each part, or use the Letter Interpreter tool to upload your own letter and get a plain-English breakdown.

If your claim is denied, or the rating is lower than you expected, you have three main lanes:

  • Supplemental Claim: refile with new and relevant evidence, such as a new nexus opinion, updated imaging, or newly located service records. See Supplemental Claim Guide.
  • Higher-Level Review (HLR): a senior reviewer looks at the same evidence again for a difference of opinion, no new evidence is added. See HLR Guide.
  • Board Appeal: your case goes to a Veterans Law Judge at the Board of Veterans' Appeals, with options for a direct review, an evidence docket, or a hearing. See Board Appeal Guide.

Not sure which lane fits your situation? See the Appeals decision guide for a side-by-side comparison of all three.

Two lanes that rarely fix an old effective date. A clear-and-unmistakable-error (CUE) motion requires an undebatable error that would have changed the outcome, a very high bar, and it is not a substitute for a timely appeal. Separately, an effective-date dispute filed after the one-year appeal window has closed is generally dismissed as untimely, regardless of its merits. File on time, and treat CUE as a last resort, not a first option.

After You Win: Maintaining Your Rating

A grant is not always the end of the story. Keep your treatment consistent, continued follow-up documenting your strength, cardinal signs, and any scar or hardware findings, protects you if VA schedules a future reexamination. A rating held at the same level for 20 years becomes protected and generally cannot be reduced. Not every rating gets reexamined; understand when a rating becomes protected from future review (including Permanent and Total status) and what to do if VA proposes to reduce it. See Protect Your Rating and Future Reexaminations for the specifics.

If your muscle injury worsens after the initial grant, for example progressing to a higher severity grade, you can file for an increased rating. See the Rating Increase Guide. And if official service records related to your injury surface later that were not in the file at the time of an earlier decision, that decision can be reconsidered as if it had never been finally decided.

Quick Reference Tables

Severity Grades at a Glance (38 CFR 4.56)

Grade What Points This Way
SevereProlonged hospitalization, scattered metal fragments on x-ray, ragged or adherent scars, measured loss of strength or muscle substance
Moderately SevereLonger-acting through-and-through or deep wound, hospitalization, a moderate number of cardinal signs consistently shown on exam
ModerateAny through-and-through or deep penetrating wound (minimum grade for the group it passed through), some cardinal signs present
SlightSimple wound or strain, minimal scar, little to no limitation of function, few or no cardinal signs

Service Connection Pathways

Pathway Mechanism Evidence Needed
DirectWound (gunshot, shrapnel, blast) or repeated strain during serviceService treatment/hospital records + nexus opinion linking the current condition to that event
Secondary, altered gait or overuseA service-connected limb or back condition changes movement patterns, overloading another muscle groupNexus opinion describing the compensating movement and its overload mechanism
Secondary, scar tissue or adhesionsScar tissue from an original wound restricts or strains an adjoining muscle groupNexus opinion tracing the adjacent group's condition back to the original wound
AggravationPre-service muscle condition worsened beyond natural progression by serviceBaseline severity before service + evidence of the in-service worsening

From Filing to Decision: Who Does What

Role Does Decides your rating?
VSO / accredited representativeHelps prepare, gather evidence, and file; represents you on appealNo
VSRDevelops the claim: orders records and the C&P examNo
C&P ExaminerConducts the exam, completes the DBQ, may give a nexus opinionNo / but has a strong impact
Rater (RVSR)Reviews the full file and decides service connection, muscle group, grade, and percentageYes

Frequently Asked Questions

How does the VA rate muscle injuries?
Muscle injuries are rated under 38 CFR 4.73 by two things: which of the 23 muscle groups was injured, and how badly it was damaged. The group sets the diagnostic code and rating scale; the damage is graded slight, moderate, moderately severe, or severe under 38 CFR 4.56, based on the cardinal signs of muscle disability and the history of the wound. Muscle codes run from 5301 to 5329.
What are the muscle groups?
The VA divides the body's muscles into 23 muscle groups, numbered I through XXIII with Roman numerals. Each group is organized by body region and by the movement its muscles perform, for example the muscles that flex the shoulder or extend the knee. The group your injury falls into determines which diagnostic code (5301 to 5329) and rating scale applies.
What makes an injury "severe" instead of "moderate"?
The grade comes from the cardinal signs of muscle disability (loss of power, weakness, lowered threshold of fatigue, fatigue-pain, impaired coordination, and uncertainty of movement) plus the history of the wound. A through-and-through or deep penetrating wound, debridement, prolonged infection, retained metal fragments, muscle tissue loss, and deep or adherent scarring all point toward severe. A small, clean, well-healed wound points toward the lower grades.
Can a muscle injury and a joint condition both be rated?
Yes, they can. A muscle-group rating (4.73) and a limitation-of-motion rating for the joint the muscle moves (4.71a) measure different things. Under 38 CFR 4.55 they are weighed together rather than one simply canceling the other, so a serious muscle wound and a limited joint can both count in the claim.
Do retained shrapnel fragments raise the rating?
They can. Retained metal fragments in the muscle are part of the wound history that pushes the severity grade higher under 38 CFR 4.56, along with things like a through-and-through wound, debridement, muscle tissue loss, and deep scarring. Imaging that shows the fragments still in the muscle is useful evidence.
Can a muscle injury be service connected secondary to another condition?
Yes. Two recognized secondary pathways are an altered gait or overuse compensation caused by a service-connected condition in another limb or the back, and scar tissue or adhesions from an original wound that strain an adjoining muscle group. Either way, a medical nexus opinion needs to explain the specific mechanism connecting the already service-connected condition to the new muscle condition.
Is a clear-and-unmistakable-error (CUE) motion a good way to fix an old rating?
Rarely. A CUE motion requires an error that is undebatable and would have changed the outcome, a very high bar. Motions to backdate a decades-old muscle-injury grant often fail because the older records don't clearly document the disability at that time. A timely appeal within the normal one-year window is a far more reliable path than waiting and later filing a CUE motion.
Disclaimer. This guide is written for educational purposes and describes how the VA's rules and regulations work in general. It is not legal advice, and it does not create any attorney or representative relationship. It is drawn from a review of published Board of Veterans' Appeals decisions, which are not binding on other cases and do not set VA policy, so it shows patterns, not promises. Individual claims have unique facts, and outcomes depend on the specific evidence presented. Veterans seeking help with their claims should work with a VA-accredited VSO representative, claims agent, or attorney, and should not pay for basic help, accredited representatives are free. The laws, regulations, and benefit rates referenced in this guide are current as of July 2026. Verify current rules at VA.gov or eCFR or through your VSO. Find an accredited representative →

Sources

  1. 38 CFR § 4.73, muscle injury diagnostic codes 5301 to 5329
  2. 38 CFR § 4.56, evaluation of muscle disabilities (slight, moderate, moderately severe, severe)
  3. 38 CFR § 4.55, multiple muscle group injuries
  4. 38 CFR § 4.14, avoidance of pyramiding
  5. 38 CFR § 4.40, 4.45, 4.59, functional loss and painful motion
  6. 38 CFR § 4.3, 4.7, reasonable doubt and the higher of two ratings
  7. 38 CFR § 3.303, basic rules for service connection, and § 3.303(d), disease diagnosed after service
  8. 38 CFR § 3.310, secondary service connection
  9. 38 CFR § 3.306, aggravation of a pre-service disability
  10. 38 CFR § 3.156, new and material evidence, including 3.156(c) newly found service records
  11. 38 CFR § 3.307, 3.309, chronic and presumptive conditions; 38 CFR § 3.317, Gulf War undiagnosed illness
  12. 38 CFR § 3.105, clear and unmistakable error
  13. 38 CFR § 3.951, protection of ratings after 20 years
  14. 38 CFR § 3.102, benefit of the doubt; 38 USC § 5107(b), same, in statute
  15. 38 USC § 1110, 1131, basic service connection; 38 USC § 1155, rating schedule; 38 USC § 5108, reopening a claim
  16. Brammer v. Derwinski, 3 Vet. App. 223 (1992), a current disability is required for a valid claim
  17. Reonal v. Brown, 5 Vet. App. 458 (1993), a medical opinion based on an inaccurate factual premise has no probative value
  18. Jandreau v. Nicholson, 492 F.3d 1372 (Fed. Cir. 2007), competency of lay testimony regarding observable symptoms versus complex medical causation
  19. Grantham v. Brown, 114 F.3d 1156 (Fed. Cir. 1997), timely appeal of a distinct issue such as the rating percentage or effective date

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