ICD code S20.01XS – Right breast contusion, sequela

Key takeaways

S20.01XS is the billable ICD-10-CM code for contusion of right breast, sequela, and it needs all seven characters to be valid.

The X in the sixth position is a required placeholder, because the S20.01 subcategory has only five characters.

The S suffix marks a sequela visit for a condition left by the bruise, not routine follow-up while the bruise heals.

The residual condition, such as breast pain or fat necrosis, is listed first, and S20.01XS follows it as the cause.

Laterality sits in the subcategory: S20.01 is the right breast, S20.02 the left, and S20.00 an unspecified breast.

ICD-10 Code S20.01XS: Definition and billable status

ICD-10 Code S20.01XS is the billable ICD-10-CM code for contusion of right breast, sequela. You assign it when a patient is seen for a condition left by an earlier right breast bruise. By then, the bruise itself is no longer being treated.

The code is valid in the FY2027 ICD-10-CM code set, which runs from October 1, 2026, to September 30, 2027. Each character segment confirms one fact about the encounter.

S20.01 on its own is not a billable code, and neither is S20.01S. The ICD-10-CM Official Guidelines from CMS require the X placeholder wherever a code has fewer than six characters and needs a 7th character. A claim with the truncated code is rejected as invalid before it reaches the payer.

You can confirm the descriptor and its validity in the CDC/NCHS ICD-10-CM browser tool. Check it again after each October 1 update.

What the 7th character S means for a right breast contusion

The 7th character tells the payer what kind of encounter this is. The S20 category takes three values, and the choice turns on whether the bruise itself is still being treated.

Section I.C.19.a of the official guidelines adds the S only to the injury code, never to the code for the residual condition. Section I.B.10 sets no time limit on sequela coding. A sequela visit can come one month or several years after the injury, as long as the provider documents the link.

The path below puts the three choices side by side and shows how the claim is ordered once S applies.

Sibling codes and how S20.01XS fits the hierarchy

S20.01XS sits in subcategory S20.0, Contusion of breast. The siblings below differ by laterality or by encounter type, and both choices come straight from the note.

Do not confuse this code with S20.142S, which describes external constriction of part of the left breast, sequela. That code sits in subcategory S20.14 and covers a different injury on the other side.

Includes and excludes notes for breast contusion coding

The notes at the block and category level decide which other codes can appear with S20.01XS. Most of them point to injuries coded elsewhere in Chapter 19.

• Block S20-S29 includes: Injuries of the breast, the chest wall and the interscapular area.
• Block S20-S29 Excludes2: Burns and corrosions (T20-T32), frostbite (T33-T34), and effects of a foreign body in the bronchus, esophagus, lung or trachea. Injuries of the axilla, clavicle, scapular region and shoulder are coded elsewhere too.
• Chapter 19 instruction: Use a secondary code from Chapter 20 to show the cause of the injury.

An Excludes2 note means the excluded condition is not part of this code. Both codes can appear on one claim when the patient has both conditions.

Additional codes required when reporting S20.01XS

A sequela claim never carries S20.01XS on its own. It needs the code for the condition being treated and, where your payer or state requires it, an external cause code.

Residual condition codes

These are common reasons a patient returns after a breast bruise. Code the condition the provider documents, not the one that seems most likely.

• N64.4 Mastodynia: Persistent breast pain attributed to the earlier injury.
• N64.1 Fat necrosis of breast: A firm lump formed by damaged fatty tissue after trauma.
• N64.51 Induration of breast: Hardened tissue at the injury site.
• L90.5 Scar conditions and fibrosis of skin: Scarring or fibrosis of the overlying skin.

External cause codes

External cause codes from Chapter 20 describe how the injury happened. At a sequela visit, they take the same S 7th character as the injury code.

Place of occurrence (Y92), activity (Y93) and external cause status (Y99) codes are reported only once, at the initial encounter. Leave them off the sequela claim. No national rule requires external cause codes, but many payers and state reporting programs ask for them.

Correct code sequencing for a sequela claim

The order of the codes tells the payer why the patient was seen. Follow this order on every sequela claim for a clean claim submission:

1. Residual condition first. The condition treated today, such as N64.1 for fat necrosis, goes in the primary position.
2. S20.01XS second. It records the injury that caused the residual condition.
3. External cause code third, if reported. It carries the S 7th character too, such as W19.XXXS.

Putting S20.01XS first is the most common sequencing error on these claims. The payer then sees a bruise as the main diagnosis with no active treatment for it, and the claim can be denied for medical necessity.

Documentation requirements for a breast contusion sequela

The record must support three facts: the injury was a contusion, it was on the right breast, and it caused the condition treated today. Without all three, the code will not hold up in an audit. This checklist follows standard medical billing compliance requirements:

• Original injury: The note confirms a contusion of the right breast. A summary of care from another facility is acceptable.
• Date of injury: Record it if known. It is not required for the code, but payers may ask for it in a review.
• Causal link: The provider states that the current condition results from the earlier contusion. “History of right breast contusion” alone does not establish a sequela.
• Named residual condition: The condition treated today is stated in the note and coded separately, ahead of S20.01XS.
• Authentication: The treating provider signs the note for the current visit, following Medicare and payer signature rules.

Query the provider whenever the note mentions the earlier injury but does not link it to today’s complaint. A coder should never infer the link from timing or location alone.

Common claim denial reasons for S20.01XS

Most denials on this code trace back to the 7th character, the sequencing, or a missing causal statement. These patterns come up in denial management workflows for sequela claims.

Track these against your medical billing denial codes to see which error recurs in your practice. A repeat pattern usually points to a template or training fix.

Payer and Medicare considerations for sequela codes

Medicare has no coverage policy specific to breast contusion sequela codes. The official guidelines on sequela coding apply, and the residual condition must meet the usual medical necessity standard.

• Medical necessity: The residual condition coded first must need evaluation or treatment, not just appear in the history.
• Timely filing: Medicare claims must be filed within 12 months of the date of service. A sequela found years after the injury does not extend that window.
• Coordination of benefits: Car crashes and workplace injuries often involve liability or workers’ compensation coverage. Watch your electronic remittance advice for adjustment reason code 22, which means another payer may cover the care.

Commercial payers set their own rules for sequela visits. Check each payer’s policy in its provider portal before you bill the visit.

How Pabau helps keep sequela claims clean

Sequela claims fail on details that are easy to miss when the note, the codes and the claim live in different places. A coder has to cross-check the 7th character, the sequencing and the causal statement by hand.

Pabau, the practice management and billing platform we build, keeps the visit note, the diagnosis codes and the claim in one patient record. Its claims management software scrubs every claim for missing or invalid details before it leaves Pabau. Claims then go out electronically through the Claim.MD clearinghouse.

The outcome is fewer rejected claims to rework, so your team spends less time on appeals.

Send sequela claims out clean the first time

Pabau keeps the visit note, the diagnosis codes and the claim in one record. Every claim is scrubbed for missing or invalid details before it leaves Pabau.

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Conclusion

S20.01XS is simple to code once the note does its job. Confirm the bruise has resolved, name the condition it left behind, and list that condition first. Then check that the X placeholder and the S are both in place.

The checks that matter happen before the claim is built, when a coder can still query the provider. Book a demo to see how Pabau keeps your sequela notes, codes and claims in one place.

Continue your research

Want to understand what goes into a clean claim? Medical billing fundamentals outlines the end-to-end process from encounter documentation through payment posting.

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