ICD code S42.361G – Right humeral shaft segmental fracture, delayed healing

Key takeaways

S42.361G codes a displaced segmental fracture of the right humeral shaft at a follow-up visit where the provider documents delayed healing.

The 7th character G means subsequent encounter with delayed healing. It is not a sequela character, and the sequela code for this fracture is S42.361S.

Aftercare Z codes such as Z47.89 are not used for a healing fracture. Guideline I.C.21.c.7 points you to the injury code with a subsequent-encounter character.

Once the provider documents nonunion or malunion, switch to S42.361K or S42.361P, and bill the repair procedure against that code.

Delayed-healing visits inside a 90-day global surgical period are usually bundled, so check the fixation date before you bill an E/M visit.

What is ICD-10 code S42.361G?

ICD-10 code S42.361G is the billable code for a displaced segmental fracture of the right humeral shaft, at a follow-up visit with delayed healing. You use it after active treatment, when the provider documents that the fracture is uniting more slowly than expected.

A segmental fracture breaks the shaft in two places and leaves a separate middle segment of bone. That segment can lose part of its blood supply, which is one reason these fractures are prone to slow healing. “Displaced” means the fragments have moved out of alignment, and “right arm” sets the laterality.

The code sits in Chapter 19 of ICD-10-CM and is valid in the FY2027 code set, effective October 1, 2026, per the CMS ICD-10-CM files.

Understanding the 7th character G in S42.361G

The 7th character G means subsequent encounter for fracture with delayed healing. It tells the payer two facts at once. The patient has already had active treatment, and the fracture is behind its expected healing timeline.

G is not a sequela character. A coder who reads it as “late effect” bills the wrong phase of care. The sequela code for this fracture is S42.361S, which reports a condition left behind after the fracture has healed.

Delayed healing also differs from nonunion. With delayed healing, union is still expected but is coming slowly. Nonunion, coded with K, means the provider has documented that the fracture has failed to unite. The flow below shows where G sits in one fracture’s care, from fixation to sequela.

S42.361 code family: All 7th character variants

Category S42 uses seven 7th characters. Unlike the forearm, femur and lower leg categories, it has no separate open-fracture characters for subsequent care. Codes such as S42.361M or S42.361R therefore do not exist.

The open or closed distinction only matters at the initial encounter. A fracture that was open at injury still takes G at a delayed-healing follow-up.

How to choose between D, G, K, P and S

The choice turns on what the provider writes about union at this visit. A coder cannot assign delayed healing from the calendar or from their own reading of an X-ray.

Sequela coding follows its own rule. The code for the late effect, such as stiffness, is listed first, and S42.361S is added to show its cause.

When the note is silent or contradictory, query the provider before you pick a character. A one-line query costs less than a denied claim and a corrected resubmission.

Documentation that supports delayed healing

A note that supports G shows an earlier active-treatment encounter, today’s follow-up, and the provider’s statement that healing is delayed. Payers reviewing these claims look for the following elements.

• Laterality stated as the right arm, matching the code.
• The fracture pattern recorded as segmental and displaced, ideally citing the imaging report.
• The date of injury, plus the date and type of the initial treatment.
• An explicit provider statement of delayed healing or delayed union, with the finding behind it.
• Current imaging findings, such as limited callus or a persistent fracture line.
• The plan for slow healing, such as longer immobilization, a bone stimulator or a surgical referral.

Where they apply, record the factors that explain the delay, such as smoking or diabetes. They support medical necessity for extra imaging, therapy or a bone stimulator.

Aftercare rules and ICD-10-CM guidelines

Aftercare Z codes are not used for injuries. ICD-10-CM guideline I.C.21.c.7 tells you to assign the acute injury code with the 7th character D for aftercare of an injury. Z47.89 therefore does not belong on a claim for this healing fracture.

When healing is delayed, the subsequent-care character changes from D to G for that visit. The new character replaces D, so never list S42.361D and S42.361G together on the same claim.

The fracture guidelines in ICD-10-CM guideline section I.C.19.c.1 handle complications the same way. Nonunion takes K and malunion takes P, rather than a separate complication code.

External cause codes are optional unless your payer or state requires them. If you report one, it takes the 7th character D, because external cause codes only take A, D or S as their 7th character. Keeping these rules in your medical billing compliance checks prevents repeat errors.

CPT codes commonly billed with S42.361G

The procedures billed at a delayed-healing visit follow the plan for a slow-healing fracture. Monitoring, imaging, therapy and bone stimulation are the usual pairings. Most of these visits include serial humerus X-rays under 73060, so the provider can compare callus at both fracture sites.

Check bone stimulator coverage before you order one. Many payers, including Medicare’s national coverage determination for osteogenic stimulators, cover them for documented nonunion rather than delayed healing.

Surgical procedures change the diagnosis. Repair of a humeral nonunion or malunion (24430, or 24435 with autograft) pairs with S42.361K or S42.361P. A humeral osteotomy (24400) to correct malunion pairs with S42.361P, not G.

Physical therapists bill 97110 and their evaluation codes under the diagnosis the referring provider documented. If the referral still says routine healing, ask for the updated note before you switch to G.

The global-period trap for delayed-healing visits

Many displaced segmental shaft fractures are fixed surgically, with CPT 24515 (plate and screws) or 24516 (intramedullary implant). Both carry a 90-day global period, which covers related follow-up care by the operating surgeon.

A delayed-healing check inside that window counts as related care, so a separate E/M visit is usually bundled and denied with CO-97. Report 99024 for tracking instead, still with S42.361G as the diagnosis.

The picture changes when the surgeon returns the patient to the operating room for a related procedure, such as revision fixation. That claim needs modifier 78, and a missing modifier draws a CO-4 denial.

Common coding errors and how to avoid them

1. Reading G as sequela. G means delayed healing at a subsequent encounter. A healed fracture with a late effect takes S42.361S, with the late-effect condition listed first.
2. Keeping D after the provider documents slow healing. Once the note says healing is delayed, use G for that visit. Code each visit from that visit’s note.
3. Using G for nonunion or malunion. If the provider documents nonunion, use K. If the fracture healed out of alignment, use P.
4. Using aftercare Z codes. Z47.89 is not used for a healing injury. Use the injury code with the subsequent-encounter character, per guideline I.C.21.c.7.
5. Using an M84 code for malunion. M84 codes cover nontraumatic bone continuity problems, such as stress and pathological fractures. Malunion of this traumatic fracture is S42.361P.
6. Wrong laterality or displacement. S42.362G is the left arm and S42.364G is a nondisplaced right fracture. Match both details to the imaging report.

Claim denial reasons and how to appeal

When a claim with S42.361G is denied, the claim adjustment reason code names the objection. A steady denial management workflow stops the same error repeating across claims.

• CO-11 (diagnosis inconsistent with the procedure): common when nonunion repair (24430) is billed with G instead of K as the 7th character. Match the 7th character to the indication for the procedure.
• CO-4 (procedure code inconsistent with the modifier, or a required modifier is missing): usually a missing modifier 78 on a return to the operating room. Check every procedure inside a global period for its modifier.
• CO-97 (included in another service): a delayed-healing E/M visit inside the 90-day global after 24515 or 24516. Report 99024 instead.
• CO-50 (not deemed medically necessary): often a bone stimulator or extra imaging without documented slow healing. Appeal with the radiology report and the provider’s statement.

For an appeal, attach the imaging report that shows slow progress and the note that names delayed healing. Add the date of the original fixation, so the reviewer can see whether a global period applies.

Tracking these medical billing denial codes by code family shows where documentation breaks down. Your revenue cycle management reports can flag S42.361 denials separately.

Related ICD-10-CM codes for S42.361G

These neighboring codes are the ones most often confused with S42.361G. Check laterality, displacement and healing status before you submit.

Avoid S42.363G when the note names the side, because payers often question unspecified laterality on fracture claims. Confirm each descriptor in the AAPC ICD-10-CM code lookup before submission.

How Pabau supports accurate fracture follow-up coding and claims

Delayed-healing claims fail when the visit note and the claim tell different stories. A coder reads a free-text note, guesses the healing status, and learns from the remittance that the guess was wrong.

Pabau, the practice management platform we build, keeps the clinical note, the diagnosis and the invoice in one patient record. A structured follow-up form captures healing status at every visit, so the coder picks D, G, K or P from what the provider recorded.

Pabau’s Claim.MD integration then submits the claim electronically to US payers and brings remittance data back to the record. Denials such as CO-97 or CO-11 appear against the visit that caused them. The claims software for practices then shows which follow-up notes keep producing the same denial.

Code every fracture follow-up visit correctly

Pabau links each visit note to its diagnosis and claim. Delayed-healing encounters go out with the right 7th character and the documentation to support it.

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Conclusion

S42.361G fits one visit type only. It is a follow-up for a displaced segmental fracture of the right humeral shaft whose healing the provider has called delayed. Treat the provider’s words about union as the deciding fact, and the 7th character follows from them.

The costly mistakes sit at the edges of that definition. Reading G as sequela turns a valid visit into a denial. So does billing Z47.89 for aftercare, or an E/M visit inside a surgical global period.

Practices that capture healing status in a structured field at every follow-up stop relying on coder judgment for these claims. Book a demo to see how Pabau keeps fracture notes, codes and claims aligned for orthopedic practices.

Continue your research

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Need to understand how clearinghouses validate ICD-10 codes? Medical claims clearinghouse explains how electronic claim validation works before codes reach the payer.

Coding a delayed-healing shaft fracture on the left arm? ICD-10 code S42.332G covers a displaced oblique humeral shaft fracture with delayed healing.

Has the provider now documented nonunion? ICD-10 code S42.309K walks through coding and billing a humeral shaft nonunion.

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