ICD-10 code S52.246H: Nondisplaced spiral fracture of the ulna

Key takeaways

ICD-10 code S52.246H covers a nondisplaced spiral fracture of the shaft of the ulna, with the arm not specified. The 7th character H marks a subsequent encounter for an open type I or II fracture with delayed healing.

H is the delayed healing character for open type I and II wounds. G is the closed-fracture version, and J covers open type IIIA, IIIB, and IIIC.

Two characters get swapped for H most often. E marks routine healing of the same open fracture, and M marks nonunion.

Displacement and laterality sit in the base code. S52.246 is the nondisplaced spiral ulnar shaft with no side documented, and S52.244 is the right arm.

Practice management software like Pabau helps orthopedic practices record the Gustilo grade, the healing status, and the encounter type at every follow-up.

ICD-10 code S52.246H is a billable diagnosis code for a nondisplaced spiral fracture of the shaft of the ulna. Coders apply it at a follow-up visit, once an open type I or II injury is healing more slowly than expected.

S52.246H remains valid in the FY 2026 ICD-10-CM edition, effective October 1, 2025, under CMS ICD-10-CM guidance. Every HIPAA-covered entity can submit it.

One letter decides whether the claim pays. S52.246E describes the same fracture healing on schedule, and S52.246G covers delayed healing after a closed injury. This guide walks through the full description, all 16 valid 7th characters, the Gustilo grades behind them, and the documentation each one needs.

ICD-10 code S52.246H: Quick reference

S52.246H is a specific, billable ICD-10-CM code, and every element of it has to be supported in the chart. The table below gathers the details a coder checks first. Claims management software captures them during the encounter, rather than leaving the 7th character to be reconstructed weeks later.

Full code description and clinical meaning

Seven separate facts are packed into S52.246H. Misreading any one of them puts the wrong code on the claim.

Each phrase in the description maps to something the physician has to write down:

• Nondisplaced: The fragments stayed in anatomic alignment. A displaced spiral fracture of the same shaft moves to the S52.241 to S52.243 range.
• Spiral: The fracture line winds around the bone, which points to a torsional force. Transverse fractures take S52.22-, and oblique fractures take S52.23-.
• Shaft of ulna: The break sits in the diaphysis. Upper-end ulna fractures take S52.0-, and lower-end fractures take S52.6-.
• Unspecified arm: No side is recorded anywhere in the chart. On a paired bone, that is nearly always a documentation problem rather than a genuine unknown.
• Subsequent encounter: Active treatment has finished, and the patient is back for follow-up care.
• Open fracture type I or II: The skin was breached, and the treating physician graded the wound Gustilo type I or type II.
• With delayed healing: Union is running behind schedule. That lag is the reason the visit is happening.

Displacement and laterality both live in the sixth character. S52.244 is the nondisplaced right ulnar shaft, S52.245 the left, and S52.246 the side that was never documented. Displaced spiral fractures at the same site run from S52.241 to S52.243.

The 7th character H in fracture coding

The 7th character is the most consequential element of any S52 fracture code. Leave it off and the code is invalid. S52.246 carries 16 valid options, covering initial encounters, subsequent encounters, and sequela. H encodes three facts at once. The visit is a follow-up, the original wound was open type I or II, and union is running late.

Characters I, L, and O never appear in this range, because ICD-10-CM avoids letters that resemble the numerals 1 and 0. The same 16-character set runs across the whole S52 forearm category, and across S42, S62, S72, S82, and S92 as well.

Read the table in threes. Within each healing outcome the first letter is the closed fracture. The second is open type I or II, and the third is open type III. H sits in the middle of the delayed healing row.

Gustilo open fracture classification and the H character

The Gustilo-Anderson grade decides which open fracture characters are available. A coder cannot assign B, E, H, M, or Q without a documented type I or type II wound. The CDC/NCHS ICD-10-CM tool confirms that these characters need explicit fracture-type documentation.

ICD-10-CM pairs types I and II under one set of characters, so the grade never changes the code once it lands in that pair. It still has to appear in the record for medical necessity and audit purposes. A type I wound and a type II wound both bill as S52.246H at a delayed healing follow-up.

Delayed healing, routine healing, nonunion, and malunion

Delayed healing means union is progressing, just slower than expected. Callus is forming and the fracture line is closing. That distinction is what keeps the 7th character at H rather than M for nonunion. The M character behaves the same way on other bones, as S02.651K shows at the mandible.

• Routine healing (E): The fracture is uniting on schedule, with no complication recorded.
• Delayed healing (H): Union is late, but callus formation is still moving in the right direction.
• Nonunion (M): Healing has stopped. Imaging shows a persistent fracture line and no bridging callus.
• Malunion (Q): The fracture united, but with angulation, rotation, or shortening beyond acceptable limits.

For S52.246H to hold, three things belong in the record. The physician has to state that healing is delayed, imaging has to support that statement, and the note has to show union is still underway.

Open ulnar shaft fractures are slow healers, because the wound costs the bone part of its periosteal blood supply. Delayed union here often runs alongside restricted forearm rotation and reduced grip strength. Treatment at this stage ranges from ultrasound bone stimulation, billed as CPT 20979, through to grafting under CPT 20902.

When to use S52.246H: Subsequent encounter vs. initial encounter

Use S52.246H at any visit after active treatment has ended. The character reflects what the provider is doing now, not how long ago the injury happened. Billing an initial encounter character at a follow-up is a frequent audit trigger. The same decision sits behind S52.033J and every other injury code.

Assign S52.246H when all of the following are true:

• Active treatment of the fracture is complete.
• The patient is back for aftercare, or for review of the healing complication.
• The original fracture was open, and the physician graded it Gustilo type I or type II.
• The physician note and imaging both confirm that healing is delayed.
• The record describes a nondisplaced spiral fracture of the ulnar shaft, with no side documented.

Reach for a different code when any of these apply:

• The patient is presenting for the first time with the open type I or II fracture, which takes S52.246B.
• Healing is on schedule, which makes the code S52.246E.
• The fracture was closed, which makes delayed healing S52.246G.
• The wound was graded type IIIA, IIIB, or IIIC, which makes delayed healing S52.246J.
• The chart documents a side, which requires S52.244H for the right arm or S52.245H for the left.

ICD-10-CM hierarchy and parent codes

Walking the classification tree confirms that S52.246H is the most specific code available. It also leaves an auditor a clean trail to follow. The 7th character only attaches once the base code is settled.

Only the last row is billable. S52.246 on its own is a non-billable parent, and a claim carrying six characters will reject.

Related codes: Laterality siblings and the S52.24 family

Two separate decisions sit behind every code in this range. First pick the base code that matches the documented side and displacement. Then pick the 7th character that matches the encounter and healing status. Codes such as S52.253K follow the same two-step logic on the same bone, and S52.133S applies it at the radial neck.

Once the side and displacement are settled, the 7th character does the rest. The table below lists the siblings most often confused with S52.246H.

Fracture pattern is a separate axis again. The ulnar shaft carries its own code group for each pattern, so a spiral fracture and a transverse fracture never share a base code.

Use S52.246H only when the record genuinely never states a side. Verify every code against the AAPC ICD-10-CM code lookup before submitting. Billability is set per fiscal year, so check the year you are billing.

Some claims also carry an external cause code. Those codes take a 7th character of their own, so a follow-up visit pairs with the D version, such as W19.XXXD for an unspecified fall. Payer policies differ on whether the external cause is required at a subsequent encounter.

Documentation requirements for S52.246H

Seven elements have to appear in the record before S52.246H is defensible. Medical documentation workflows that capture each one at the point of care stop denials before they start. Digital clinical forms can prompt for every data point during the visit.

• Bone and site: The note has to name the shaft of the ulna. Upper-end and lower-end ulna fractures are separate codes.
• Fracture pattern: Spiral has to be stated. A bare ulnar shaft fracture defaults to the S52.20 series.
• Displacement: The note or the radiology report has to confirm the fragments are nondisplaced.
• Open fracture: Emergency or operative documentation has to confirm the wound was open.
• Gustilo grade: The treating physician has to record type I or type II. A coder cannot grade a wound from its description.
• Delayed healing: A physician statement and imaging are both needed. A slow-looking radiograph on its own does not support H.
• Encounter type: The visit has to follow the end of active treatment, with the note reflecting aftercare or complication review.

Laterality is the eighth element, and it is the one this code gives up on. Practices using patient record management tools that prompt for structured clinical fields capture the side at the first visit. That keeps the claim on S52.244H or S52.245H instead.

Common coding errors and how to avoid them

S52.246H turns up in a predictable set of errors that generate denials and compliance risk. Codes like S42.90XG share the same weak point. The 7th character is where most of them happen.

• Submitting S52.246 with no 7th character: The parent code is non-billable. A six-character claim rejects on submission, every time.
• Using E where H belongs: E is routine healing after an open type I or II fracture. H is the same injury healing late.
• Using G where H belongs: G is delayed healing of a closed fracture. If the record documents an open wound, G understates the injury.
• Confusing delayed healing (H) with nonunion (M): H means union is late but progressing. M means it has stopped, and the documentation for each is different.
• Applying an initial encounter character at a follow-up: S52.246B covers the first visit for an open type I or II fracture. Using it at a ten-week check is an audit flag.
• Coding the radius instead of the ulna: Radial shaft fractures take S52.3-. A both-bone forearm fracture needs a separate code for each bone.
• Reaching for a distal radius code: S52.24- is the ulnar shaft. Colles’ fracture of the distal radius is a different family, S52.53-.
• Defaulting to unspecified laterality: When the side is documented, S52.244H or S52.245H is required. S52.246H is a last resort.

Four coding scenarios and the code each one takes

These four scenarios show how the letter changes with the record. Torsional forearm injuries usually land in sports medicine software first. From there the patient moves into a physical therapy EMR, where the rehab notes live.

Scenario 1: Ten-week delayed healing review. A 41-year-old returns after a twisting forearm injury. The emergency note recorded an open wound graded Gustilo type II, and radiographs showed a nondisplaced spiral fracture of the ulnar shaft. No side appears anywhere in the transferred records. At ten weeks the physician documents callus formation behind schedule. The correct code is S52.246H.

Scenario 2: The same visit, but nonunion. Imaging at 16 weeks shows a persistent fracture line and no bridging callus. The physician documents nonunion. The correct code is S52.246M, not S52.246H. Healing has stopped rather than slowed.

Scenario 3: A closed injury instead. Same bone, same pattern, and the same delayed healing finding, but the skin was never breached. The correct code is S52.246G, because G carries delayed healing for closed fractures.

Scenario 4: The side is documented. The operative report names the right ulna, and everything else matches scenario one. The correct code is S52.244H. S52.246H would give away specificity the record already supports.

Check every code against the official S52.246H code listing before each submission. Practices running HIPAA-compliant clinical documentation can produce the audit trail these codes require.

Approximate synonyms and clinical terms

Operative notes, discharge summaries, and referral letters rarely use code language. Treat any of these phrases as a signal to consider S52.246H, then verify each qualifying condition.

• Open spiral ulnar shaft fracture, Gustilo type II, delayed union on follow-up
• Nondisplaced spiral fracture of the ulnar diaphysis, type I open wound, slow to unite
• Subsequent care: Open spiral forearm fracture of the ulna with delayed healing
• Torsional ulnar shaft fracture, open type II, callus behind schedule at ten weeks
• Isolated ulnar shaft fracture, spiral pattern, open grade I, union delayed

None of these phrases replaces a code lookup. They work as pattern-recognition triggers only. Once the S52.24 family is in view, the 7th character still needs a full documentation review.

How Pabau supports accurate fracture coding workflows

Orthopedic and musculoskeletal practices hit the same wall at every fracture follow-up. The note has to carry the pattern, the displacement, the side, the Gustilo grade, and the healing status. Miss one and the coder cannot defend the 7th character, so the claim waits on a query.

Practice management software like Pabau keeps that evidence inside the clinical record. Pabau ties each diagnosis code to the encounter behind it. Your billers open the supporting note before submission, so a thin operative report is caught at the desk rather than by the payer.

Paired with medical practice scheduling software, the record separates first visits from follow-ups at the booking stage. Your team therefore settles the encounter type before the claim is generated, rather than correcting it after a denial.

Stop losing fracture follow-ups to one wrong letter

Pabau ties every diagnosis code to the encounter that supports it. Your team spots a missing Gustilo grade or healing status before the claim goes out, so open fracture follow-ups stop coming back as denials.

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Conclusion

S52.246H is narrow by design, and that is what makes it defensible. Seven facts have to line up in the record. The fracture must be nondisplaced, spiral, and in the shaft of the ulna.

The visit must be a subsequent encounter after an open Gustilo type I or II injury, with delayed healing documented. If one element is missing, the answer is a provider query rather than a best guess.

The letter is where the money sits. D, E, G, and H all describe the same broken bone at the same stage of care. Only the wound type and the healing status separate them, and M changes the healing outcome entirely.

A follow-up template that forces the clinician to name the Gustilo grade and the healing status turns a recurring denial into a routine claim. Book a demo to see how Pabau keeps those details on every fracture follow-up note.

Continue your research

Need the routine healing counterpart of H? S52.001E applies E to an unspecified fracture of the upper end of the right ulna.

Coding the radius side of the same forearm? S52.355R applies the malunion character to a comminuted radial shaft fracture.

Comparing the malunion characters on a radial neck fracture? S52.131Q walks through P, Q, and R on a displaced fracture of the neck of the right radius.

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