ICD code S73.016D – Posterior hip dislocation follow-up care

Key takeaways

S73.016D is the billable ICD-10-CM code for posterior dislocation of an unspecified hip, subsequent encounter. Its siblings are S73.016A (initial) and S73.016S (sequela).

The 6th character 6 means the side is not documented. It is not a left hip code. The left hip is S73.015D and the right hip is S73.014D.

The 7th character D applies once active treatment has ended and the patient is healing, not simply at the second visit.

When the record names the side, use the side-specific code. When it says dislocation but not the direction, use S73.006D, S73.005D or S73.004D instead.

Pabau, the practice platform we build, can record diagnosis details such as side and direction in clinical notes for billers to check.

ICD-10 code S73.016D: Code structure and official descriptor

S73.016D sits in category S73, which covers dislocation and sprain of the joint and ligaments of the hip. Each character narrows the diagnosis, and the 6th character carries both the type of displacement and the side.

The word “unspecified” in this descriptor refers to the side, not the type of dislocation. The type is known: the femoral head was displaced posteriorly, which is the most common pattern in traumatic hip dislocation. What the record does not say is whether it was the right or the left hip. Per the CDC/NCHS ICD-10-CM web tool, S73.016D is a valid billable code in the current release.

The 7th character D: What “subsequent encounter” means

The 7th character D does not mean “the second visit.” Under ICD-10-CM Official Guidelines Section I.C.19, the encounter character reflects the phase of care, not the visit count.

Active treatment ends when the provider is no longer managing the acute injury. Once the hip has been reduced and the patient is in monitored recovery, follow-up visits take the D character. That holds when the patient moves from orthopedics to physical therapy, and it holds months later.

The guidelines also rule out the aftercare Z codes for injuries. For injury aftercare, you assign the acute injury code with the 7th character D. A follow-up visit is coded S73.016D, not Z47.89.

Sequela coding applies to a different scenario. The patient presents with a late effect caused by the dislocation, such as osteonecrosis of the femoral head (M87.256 when the side is not documented). The late effect is sequenced first, and S73.016S follows it as the cause.

When to use S73.016D vs S73.016A vs S73.016S

Two questions decide the code. Has active treatment ended? And does the record name the side? S73.016D is correct only when the answer to the first is yes and the answer to the second is no. The matrix below maps each combination of direction and side to its follow-up code.

Clinical scenario walkthrough

A patient is injured in a car crash and the ED reduces a posterior hip dislocation. Here is how the code changes as the record fills in:

1. Emergency department visit (day 0): Closed reduction under sedation. The ED note says “posterior hip dislocation” but never states the side. Code: S73.016A, because the patient is receiving active treatment. A documentation query should go to the provider.
2. Ortho follow-up at two weeks: X-ray confirms the reduction holds and no procedure is performed. The visit note still says only “hip.” Code: S73.016D, because active treatment has ended and the side is not documented.
3. After the query: The provider adds an addendum stating the left hip. Correct the claim to S73.015D, posterior dislocation of left hip, subsequent encounter. S73.016D no longer applies once the side is on record.
4. Physical therapy sessions (weeks 3 through 10): The PT evaluation documents the left hip. Code: S73.015D for each session in the healing phase.
5. Return at six months with new hip pain: MRI shows osteonecrosis of the left femoral head. Code M87.252, osteonecrosis due to previous trauma of the left femur, first. Then add S73.015S as the sequela of the dislocation.

The scenario shows what S73.016D is for. It is the right code for a follow-up visit only while the side is missing from the record. If the record does not identify the side, the guidelines direct you to the unspecified-side code. Once it does, the side-specific code takes over. The CMS ICD-10 coding resources page publishes the annual guidelines that set these rules.

What S73.016D covers, and what it doesn’t

S73.016D covers follow-up care for a traumatic posterior dislocation of the hip when the side is not documented. Knowing what it excludes prevents miscoding and medical necessity denials.

Inclusions

• Follow-up after closed or open reduction of a traumatic posterior hip dislocation, where the record does not state the side
• Subsequent care by orthopedics, physical therapy or occupational therapy during the recovery phase
• Post-operative monitoring after open treatment of the dislocation
• Imaging visits to confirm the reduction holds, when no new treatment procedure is performed

Exclusions (use alternative codes)

• Side documented as left: S73.015D, posterior dislocation of left hip, subsequent encounter
• Side documented as right: S73.014D, posterior dislocation of right hip, subsequent encounter
• Direction not documented: S73.006D for an unspecified hip, or S73.005D (left) and S73.004D (right)
• Posterior subluxation rather than dislocation: S73.013D, or S73.012D (left) and S73.011D (right)
• Anterior or central dislocation: S73.026D (obturator), S73.036D (other anterior) or S73.046D (central) for an unspecified hip
• Dislocation of a hip prosthesis: T84.02- codes, not S73.0-
• Pathological, recurrent or congenital dislocation: M24.35-, M24.45- or Q65.-, because none of these is an acute traumatic event
• Hip sprain or muscle strain: S73.1- for a sprain, S76.- for a strain of hip muscle, fascia or tendon
• Bilateral dislocation: There is no bilateral code, so code each side separately

Category S73 also carries a “code also” note for any associated open wound. The AAPC ICD-10-CM lookup shows the full Excludes1 and Excludes2 notes for the category, which helps when you confirm exclusion logic during claim preparation.

Commonly confused codes in the S73 category

The S73.0 subcategory is dense, and the 6th character alone separates side and severity. These are the codes most often mixed up with ICD-10 code S73.016D:

Documentation requirements for S73.016D

Payers reviewing a claim with ICD-10 code S73.016D look for specific record elements before they pay. Understanding medical billing fundamentals helps practices build documentation habits that hold up under payer scrutiny.

Documentation checklist

• Confirmed dislocation: An imaging report (X-ray or CT) on file confirms a traumatic dislocation, not just clinical suspicion.
• Direction documented as posterior: The note or imaging report states posterior dislocation. Without the direction, the code moves to S73.006D.
• Side checked before you code: S73.016D applies only when no note in the record identifies the side. If any note says left or right, use S73.015D or S73.014D instead.
• Laterality queried: When the side is missing, send a provider query before submission. An unspecified-side code on a hip injury invites payer review.
• Phase of care documented: The note shows that the patient is in the healing phase, not receiving active procedural treatment.
• Care continuity explained: When care moves from ortho to PT, a short note confirming the injury origin prevents a D-to-A error at audit.
• Associated injuries coded separately: Acetabular fracture (S32.4-) and sciatic nerve injury (S74.0-) are coded alongside S73.016D where documented.
• CPT-ICD alignment verified: The procedure code matches what the provider did at this visit, not the original reduction.

CPT codes commonly billed with S73.016D

The CPT codes that pair with S73.016D depend on the encounter type. Because D marks a subsequent encounter, the reduction procedures from the initial visit pair with S73.016A, not S73.016D. Pabau’s claims software for practices validates claims for missing or invalid details before submission, and tracks insurer authorizations as cases.

The surgeon who performed the reduction may see the patient inside its global period. Those routine follow-ups are bundled and reported with 99024, not billed as E/M visits such as 99213. Physical therapy practices billing 97000-series codes such as 97110 should link each diagnosis to the procedure types it supports. That stops staff from carrying the reduction CPT from the initial claim into follow-up claims.

Payer coverage and reimbursement guidelines

Medicare covers follow-up care for a traumatic hip dislocation under S73.016D when medical necessity is documented. Pabau’s integrated US clearinghouse, Claim.MD, adds eligibility checks and electronic remittance advice (ERA) feedback. That lets you spot a coverage problem before submission rather than after a denial.

Key coverage points to verify with each payer:

• Medicare Part B: Outpatient ortho and PT visits during recovery are covered under Part B when medical necessity is documented. Check your MAC’s Local Coverage Determinations for any policy covering follow-up hip care.
• Prior authorization: Requirements for PT and ortho follow-up vary by commercial payer and plan year. Some payers require authorization after a set number of PT visits. Confirm with the plan before the visit, not after.
• Modifier requirements: An E/M code billed with PT procedure codes on the same claim may need modifier 25 for a significant, separately identifiable service. Modifier rules vary by carrier.
• Unspecified-side codes: Some payers review or reject claims that carry an unspecified-side injury code. Resolving laterality before submission avoids that review entirely.
• Medicaid: State Medicaid programs set their own criteria. Follow-up care for a traumatic hip dislocation is generally covered, but visit limits and authorization thresholds differ by state.

Submitting a clean claim for S73.016D means confirming eligibility before the visit, not just confirming the patient has coverage. Active coverage does not guarantee coverage for this diagnosis and procedure at this stage of care.

Common claim denial reasons for S73.016D, and how to fix them

Most denials on ICD-10 code S73.016D follow a recognizable pattern. Structured denial management workflows built around these triggers reduce rework and shorten days in accounts receivable. The medical billing denial codes that show up most often on these claims break down as follows:

How Pabau keeps hip dislocation follow-up claims accurate

In most practices, side and direction travel through free text. The ED note says “posterior hip dislocation,” the referral says “hip,” and the biller picks a code days later. By then, the note that names the side may sit two entries back, and the claim still goes out as S73.016D.

In Pabau, clinicians can record diagnosis details in clinical notes, including the side and direction of the injury. Billers see those details in the same record when they choose the code. Claim validation then checks each claim for missing or invalid details before submission.

The result is a diagnosis code that agrees with the chart it came from. You spend less time on laterality queries and resubmissions, and every Pabau subscription includes the full feature set, from notes to claims.

Keep side, direction and code in one record

Pabau keeps clinical notes and claims in one record for ortho and PT practices. It validates claims for missing or invalid details before submission, and tracks insurer authorizations as cases.

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Conclusion

ICD-10 code S73.016D is narrower than its descriptor suggests. It means a posterior dislocation at a follow-up visit, with the side missing from the record. When a chart supports it, the better move is usually a provider query. Once the side is on record, S73.015D or S73.014D takes over.

Practices that capture side and direction in structured fields avoid the code almost entirely, along with the reviews it attracts. To see how Pabau handles clinical notes, claims validation and clearinghouse submission for orthopedic and PT practices, book a demo.

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