ICD-10 code S32.416A: Nondisplaced anterior wall, no side

Key takeaways

ICD-10 code S32.416A covers a nondisplaced fracture of the anterior wall of the acetabulum when the record does not state which hip.

Laterality is unspecified for this code, so a documented right side takes S32.414A and a documented left side takes S32.415A.

The 7th character A marks the initial encounter for a closed fracture, which is the active treatment phase.

S32.416 also takes B, D, G, K, and S, so the code follows the patient from an open injury through nonunion and sequela.

Practice management software like Pabau keeps every diagnosis code attached to the encounter that produced it, so coders can see the care phase.

ICD-10 code S32.416A reports a nondisplaced fracture of the anterior wall of the acetabulum at the initial encounter, on a hip the chart never names. Every acetabular fracture happens on one side of the body, so the missing detail sits in the paperwork.

S32.416A is billable, so it will process. It also tells the payer that nobody wrote down which hip, and unspecified codes draw review. The skill is knowing when the chart genuinely lacks a side, and when to go and ask for one.

ICD-10 code S32.416A at a glance

S32.416A is a billable, specific ICD-10-CM diagnosis code valid for HIPAA-covered transactions. It describes a nondisplaced fracture of the anterior wall of the acetabulum at the initial encounter for a closed fracture.

The record does not identify which hip. Per the CMS ICD-10-CM code files, the code has been valid since the ICD-10-CM transition.

What S32.416A describes inside the hip socket

The acetabulum is the cup-shaped socket of the hip joint, formed where the ilium, ischium, and pubis fuse. It holds the head of the femur. The anterior wall is the forward-facing rim of that socket, and it carries load through hip flexion.

A nondisplaced fracture means the bone has cracked but the fragments still sit in their anatomical position. Anterior wall fractures of this kind are often managed without surgery.

High-energy trauma causes most of them. Motor vehicle collisions, falls from height, and heavy contact in sport are the usual mechanisms. In an older patient, a low fall after an episode coded R55 can be enough.

Practices that carry these patients through months of rehabilitation, often on sports medicine software, will reuse the base code many times before the episode closes.

The word “unspecified” in the descriptor is a statement about the paperwork, not about the injury. Every acetabular fracture happens on one side of the body. S32.416A only says that the record in front of the coder never names it.

Where S32.416A sits in the ICD-10-CM hierarchy

Each step down the hierarchy adds one fact to the code. Reading it from the top makes the sixth and seventh characters much easier to justify at audit.

S32.4 names the acetabulum and S32.41 names the anterior wall. The sixth character then carries displacement status and laterality together, and the seventh fixes the phase of care.

Two Tabular List notes travel with S32.4

The Tabular List carries two instructions that reach this code, and neither shows up in the Alphabetic Index.

Under S32.4, a Code Also note tells you to report any associated fracture of the pelvic ring, S32.8-. At the S32 category level, a Code First note puts any associated spinal cord or spinal nerve injury, S34.-, ahead of the fracture.

Neither note changes S32.416A itself. They change what sits beside it on the claim, and in the spinal cord case, what sits first.

High-energy pelvic trauma is exactly the setting where both notes apply, so check the rest of the imaging before you stop at one code.

The sixth character does two jobs at once

The sixth character in the S32.4 subcategory is a single value carrying both displacement and laterality. It runs through a fixed cycle of six, and the cycle repeats for every fracture pattern in the subcategory.

The same cycle covers the posterior wall at S32.42, the anterior column at S32.43, and the posterior column at S32.44.

Learn it once and you can check any acetabular fracture code without a lookup. The same pattern runs through S32.432D on the anterior column.

Two parts of the subcategory sit outside the cycle. S32.40- and S32.49- carry no displacement axis, so they run 1 for right, 2 for left, and 9 for unspecified instead.

S32.416 takes six 7th characters, not three

ICD-10-CM adds a 7th character to fracture codes to record the phase of care.

Coders who assume only A, D, and S are available lose G and K, the two characters trauma cases need most. The CDC/NCHS ICD-10-CM tool lists the full set.

There is no C option here. Gustilo open fracture types belong to the long bone categories, so an open anterior wall fracture stops at the B character. A confirmed failure to unite moves the claim to the K character, the pattern set out at S32.402K.

A physical therapy practice treating hip rehabilitation after the acute phase uses S32.416D, not S32.416A. Running the A character through a long course of rehabilitation is one of the most frequent audit triggers in trauma billing.

No billing tool will catch that for you, as someone has to read the phase of care at each visit, then pick the character to match.

The six anterior wall codes, side by side

S32.416A sits in a block of six anterior wall codes. Three are displaced and three are nondisplaced, and within each group the only difference is which hip the record names.

Nearby codes that get picked by mistake

Most misassignments come from one of two moves. A coder either drops the wall detail and climbs to a broader code, or keeps the wall and picks the wrong one.

You can confirm any of these against the AAPC ICD-10-CM code lookup or the NLM Clinical Tables search. The dome pattern is worked through in full at S32.484A.

Use S32.416A only after you have searched the chart

Use S32.416A when the record documents the anterior wall, documents nondisplacement, and never states a side. That combination is uncommon, but it happens. Portable imaging, transferred records, and dictation that says only “the hip” all produce it.

Do not use it as a shortcut. The ICD-10-CM Official Guidelines let laterality come from clinicians other than the treating provider, so a radiologist naming the side is enough. The FY 2026 guidelines set that out in section I.B.13.

A side documented anywhere in the chart moves the claim to S32.414A or S32.415A. Where two clinicians disagree on the side, the guidelines say to query the provider rather than default to the unspecified code.

Payers also track unspecified code use at the provider level. A practice whose acetabular fracture claims run heavily to a sixth character of 6 will draw questions long before any single claim is denied.

How it plays out on one chart

A patient arrives by ambulance after a motorcycle collision. The trauma note records pelvic pain and nothing more. CT reports a nondisplaced anterior wall acetabular fracture with no side stated, and the orthopedic consult repeats the finding the same way.

At this point S32.416A is defensible. The coder queries anyway, and the surgeon answers “left” the next morning. The claim goes out as S32.415A, and the query stays in the record as the reason the code changed.

Synonyms and index terms that lead to S32.416A

Clinicians rarely write the code descriptor word for word. These phrasings all describe the same injury, with no side recorded.

• Closed nondisplaced fracture of the anterior acetabular wall
• Nondisplaced anterior wall fracture of the hip socket
• Anterior wall acetabular fracture, nondisplaced, side not documented
• Nondisplaced fracture of the anterior acetabulum, closed, first visit

In the Alphabetic Index the path runs Fracture, traumatic, acetabulum, anterior wall, which points to the S32.41- block.

The Index never supplies the sixth and seventh characters, so the Tabular List completes the code. Assigning from the Index alone is how the wrong laterality reaches a claim.

What the record must show to support S32.416A

Payers and auditors expect the record to support every character in the code, including the one that says the side is unknown.

Structured digital intake forms that capture the injury mechanism and the affected side at first presentation stop most of these problems early.

• Laterality: no clinician has named a right or left hip anywhere in the record. If one has, code S32.414A or S32.415A instead.
• Anatomical location: documentation identifies the anterior wall, not just an acetabular fracture. The radiology report is the primary source.
• Displacement status: a radiologist or treating clinician records the fracture as nondisplaced. If displacement is not addressed at all, ICD-10-CM defaults to displaced.
• Fracture classification: the note confirms a closed fracture, with no open wound communicating with the fracture site.
• Encounter type: the visit falls in the active treatment phase, which is what supports the 7th character A.
• Query trail: any attempt to clarify the side is documented, so the unspecified code reads as a last resort rather than a default.

Keeping those elements in one place is a records problem before it is a coding problem. Patient record management tools that flag incomplete fields let the coder see the radiology report, the operative note, and the query in the same view.

Five steps from the radiology report to S32.416A

Step 1: Confirm the fracture is in the acetabulum

Pelvic ring fractures and femoral neck fractures sit in different code families. The record has to place the fracture in the hip socket itself, usually on CT or a dedicated pelvic view.

Step 2: Confirm the anterior wall

The subcategory splits by wall, column, dome, and transverse pattern. If the report names only “acetabular fracture”, the code moves up to S32.409A rather than into the anterior wall block.

Step 3: Confirm the fracture is nondisplaced

Nondisplaced has to be stated. Silence is not the same as absence, and ICD-10-CM treats an unaddressed displacement status as displaced, which would give S32.413A.

Step 4: Search the record for laterality

Read past the diagnosis line. Check the imaging order, the radiology impression, the nursing notes, and any transfer paperwork. Only when none of them names a side does the sixth character stay at 6.

Step 5: Add the 7th character

Match the character to the phase of care rather than the visit number. Active treatment takes A, expected healing takes D, and stalled healing takes G or K.

How the claim moves, and where it stalls

S32.416A goes onto the claim beside the CPT code, the scrubber runs the payer’s edits, and the file leaves as an 837P or a CMS-1500. Where a payer’s policy expects laterality on acetabular fractures, the rejection lands as a front-end edit, days before adjudication.

Open treatment usually needs prior authorization first, and the diagnosis code on that request should match the one that later reaches the claim. Claims management software keeps every claim, its status, and its supporting documents in one view.

Before you submit, run these six checks

• Has any clinician named a right or left hip anywhere in the chart?
• Does the record state “nondisplaced” in words, rather than leaving displacement open?
• Does the 7th character match the phase of care on this date of service?
• Is there an associated pelvic ring fracture that needs an S32.8- code beside this one?
• Is the CPT code on the claim consistent with a nondisplaced, closed fracture?
• If the side was queried and nobody answered, is that query in the record?

The mistakes that turn S32.416A into a denial

S32.4 is granular and shortcuts are tempting, which makes acetabular fractures a high-denial family. Every code on the claim also has to stay valid for HIPAA-covered transactions. These are the errors that recur.

• Reading S32.416A as the left-side code: it is the unspecified code. Left is S32.415A and right is S32.414A.
• Using unspecified as a default: reach for S32.416A only after the chart has been searched and a query has been considered.
• Missing the 7th character: S32.416 submitted without a seventh character is an invalid code and the claim will reject.
• Displaced versus nondisplaced: where displacement is not documented, the default is displaced, which moves the code to S32.413A.
• Wrong character for the care phase: leaving A on routine follow-up visits. Switch to D once active treatment ends, then to G or K if healing stalls.
• Climbing to a parent code: S32.409A throws away the anterior wall detail that the record does support.
• Open fracture confusion: S32.416A is for closed fractures only. An open anterior wall fracture with no documented side is S32.416B.

Most of these share one cause. Care moves into the next phase and the code stays where it was. A physical therapy EMR puts the previous diagnosis in front of whoever writes the next note, which makes the change harder to forget. Choosing the new character is still a human decision.

CPT codes that pair with S32.416A on a claim

Diagnosis codes and procedure codes are assigned independently, but payers compare them on the same claim.

A surgical fixation code sitting beside a nondisplaced diagnosis invites review, and so does closed treatment beside a displaced one.

One of those lines can settle the laterality question on its own. Check whether the practice billed a unilateral hip radiograph with an RT or LT modifier on the same date. If it did, the side is documented somewhere, and the diagnosis code should follow it.

ICD-9-CM crosswalk for S32.416A

Practices reviewing legacy records still meet the ICD-9-CM equivalent. CMS published the General Equivalence Mappings as a transition aid and stopped updating them once the transition period closed.

ICD-9-CM never captured laterality, displacement status, or the specific wall. Because 808.0 maps to many ICD-10-CM codes, the clinical documentation decides the code, and the crosswalk only narrows the field.

How Pabau keeps the missing side from reaching the claim

Most practices meet the laterality problem after the fact. The claim goes out with an unspecified code, the denial arrives weeks later, and someone reopens a chart that is now several visits old.

Practice management software like Pabau moves that check earlier. Intake forms capture the affected hip before the clinician starts writing.

The imaging report, the clinical note, and any coder query then sit on one patient record, attached to the encounter that produced them.

So the coder is not chasing three systems for one word. Billing runs from the same record, and claim status is visible in one place. A stalled claim surfaces in days, rather than in a payer letter.

Keep records, coding, and claims in one place

Pabau brings the patient record, the clinical note, and the claim together for orthopedic and physical therapy practices. Coders work from one screen, and billing staff can see where every claim stands.

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Conclusion

S32.416A is a precise code about an imprecise record. It reports a nondisplaced anterior wall acetabular fracture at the initial encounter, on a hip the chart never identifies. Anyone reading it as the left-sided code is reaching past S32.415A.

The habit worth building is a small one. Search the whole chart before you settle for the unspecified sixth character, and query when a side is hinted at but never written down. That single step keeps your unspecified rate low and your acetabular claims out of review queues.

Holding the notes, the codes, and the claim on one record is what makes that habit easy to keep. Book a demo to see how Pabau does it for orthopedic and physical therapy practices.

Continue your research

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