S56.821A vs S56.822A

S56.821A (Laceration of other muscles, fascia and tendons at forearm level, right arm, initial encounter) compared with S56.822A (Laceration of other muscles, fascia and tendons at forearm level, left arm, initial encounter), from the official CMS tabular data.

Summary

These codes name the same condition on opposite sides of the body, so the documented side decides which one applies.

MedCoder-derived

What is different?

Title wording.The titles differ in one word, “right” (S56.821A) versus “left” (S56.822A): S56.821A is “Laceration of other muscles, fascia and tendons at forearm level, right arm, initial encounter”; S56.822A is “Laceration of other muscles, fascia and tendons at forearm level, left arm, initial encounter”.

Registry fact

Can these codes be reported together?

One side per condition.S56.821A and S56.822A name the same condition on opposite sides of the body. Same category and title, differing only in which side is affected — the documentation decides which one applies, and a bilateral code is reported only where the code set provides one.

MedCoder-derivedGuide: Laterality coding

Is there an Excludes1 relationship?

None.Neither entry carries an Excludes1 note that names the other code.

Official rule

Is there an Excludes2 relationship?

None.Neither entry carries an Excludes2 note that names the other code. S56.821A carries 6 Excludes2 notes and S56.822A carries 6 Excludes2 notes covering other codes; the side-by-side table quotes them.

Official rule

Is one more specific?

No.Neither is a subdivision of the other, and neither title is the unspecified form; they describe different conditions within category S56.

Registry fact

Is one a parent or header code?

No.Both are billable codes, and neither contains the other.

Registry fact

Are there sequencing instructions?

None.Neither entry carries a Code First or Use Additional Code note that names the other.

Official rule

Are there other coding relationships?

Yes.Same condition, opposite side. S56.821A and S56.822A name the same condition on opposite sides of the body.

MedCoder-derivedGuide: Laterality coding

Official rule: a tabular instructional note or a section of the ICD-10-CM Official Guidelines, quoted as published. Registry fact: the codes’ own published attributes (titles, billable status, position in the hierarchy, code set). MedCoder-derived: a reading MedCoder computes from those facts; it is not itself a rule.

Can these codes be reported together?

Review

Laterality relationship

S56.821A

Right

Laceration of other muscles, fascia and tendons at forearm level, right arm, initial encounter

↔

S56.822A

Left

Laceration of other muscles, fascia and tendons at forearm level, left arm, initial encounter

What we found

Same condition, opposite side.S56.821A and S56.822A name the same condition on opposite sides of the body.

Same category and title, differing only in which side is affected — the documentation decides which one applies, and a bilateral code is reported only where the code set provides one.

What to review

Report the side the documentation names. Where the code set provides a bilateral code and both sides are documented, use it instead of the pair.

Guide: Laterality coding Check these on a claim

Why it matters

These codes share a category and title and differ only in the side affected. The documentation decides which applies, and a bilateral code is reported only where the code set provides one.

Source / rule

ICD-10-CM tabular list (laterality variant derived from the code title)

Side by side

	S56.821ALaceration of other muscles, fascia and tendons at forearm level, right arm, initial encounter	S56.822ALaceration of other muscles, fascia and tendons at forearm level, left arm, initial encounter
Billing status	Billable	Billable
Classification	S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)	S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)
Definition	Laceration of other muscles, fascia and tendons at forearm level, right arm, initial encounter is a billable ICD-10-CM diagnosis code (S56.821A).	Laceration of other muscles, fascia and tendons at forearm level, left arm, initial encounter is a billable ICD-10-CM diagnosis code (S56.822A).
7th character	The appropriate 7th character is to be added to each code from category S56	The appropriate 7th character is to be added to each code from category S56
Excludes2	injury of muscle, fascia and tendon at or below wrist (S66.-) sprain of joints and ligaments of elbow (S53.4-) burns and corrosions (T20-T32) frostbite (T33-T34) injuries of wrist and hand (S60-S69) insect bite or sting, venomous (T63.4)	injury of muscle, fascia and tendon at or below wrist (S66.-) sprain of joints and ligaments of elbow (S53.4-) burns and corrosions (T20-T32) frostbite (T33-T34) injuries of wrist and hand (S60-S69) insect bite or sting, venomous (T63.4)
Code also	any associated open wound (S51.-)	any associated open wound (S51.-)

Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on.

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Derived from the official CMS ICD-10-CM tabular data (FY2026). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources