ICD-10 Code M24.7: Protrusio acetabuli

Key takeaways

ICD-10 Code M24.7 is the billable, specific diagnosis code for protrusio acetabuli, valid for fiscal year 2026.

M24.7 carries no laterality subcodes, so coders assign the same code regardless of which hip is affected.

Secondary causes such as rheumatoid arthritis, Paget’s disease, and osteomalacia must be documented and coded alongside M24.7.

Practice management software like Pabau lets clinicians assign ICD-10 codes inside the patient record. That removes the tab-switching between a reference site and a billing system.

ICD-10 Code M24.7 is the billable ICD-10-CM diagnosis code for protrusio acetabuli, a hip disorder in which the socket protrudes into the pelvic cavity. It is valid for fiscal year 2026 and carries no laterality subcodes.

The detail that decides most M24.7 claims is whether the note names a secondary cause. This reference covers the code structure, clinical context, documentation requirements, related codes, and billing.

What ICD-10 Code M24.7 covers

M24.7 is a billable, specific ICD-10-CM diagnosis code for protrusio acetabuli. Billable means the code carries enough clinical detail to appear on a claim for reimbursement. According to the CDC/NCHS ICD-10-CM tool, M24.7 is valid for fiscal year 2026, covering October 1, 2025 through September 30, 2026. Verify validity each October 1, when the annual update cycle takes effect.

Unlike many entries in the M24 category, M24.7 does not carry laterality suffixes. There is no M24.71 for the right hip or M24.72 for the left. Fracture codes such as S42.131K carry a laterality digit, and M24.7 does not. The single code covers every presentation, which simplifies assignment but still leaves the note responsible for naming the affected hip.

Where the code sits in the ICD-10-CM hierarchy

Knowing the parent-code chain helps when you are answering a documentation audit or appealing a payer denial. M24.7 sits four levels deep in ICD-10-CM, and each level narrows the clinical scope.

• Chapter M00-M99: Diseases of the Musculoskeletal System and Connective Tissue
• Block M20-M25: Other joint disorders
• Category M24: Other specific joint derangements
• Code M24.7: Protrusio acetabuli (billable/specific)

The CMS ICD-10 codes page publishes the full tabular list each fiscal year. Check the complete M24 category annually, because adjacent codes occasionally pick up validity changes that a saved favorites list will not show you.

What is protrusio acetabuli?

Protrusio acetabuli is a hip joint disorder in which the acetabulum, or hip socket, protrudes medially into the pelvic cavity. The femoral head is displaced inward beyond the ilioischial line. That reduces joint space and restricts range of motion.

The condition presents in two forms. Primary or idiopathic protrusio acetabuli has no identified underlying cause and tends to occur in young women. Secondary protrusio acetabuli develops from a systemic or traumatic process that affects bone integrity.

Causes and risk factors

Secondary causes are more common in practice, and they are where the coding work sits. Each underlying condition has its own ICD-10 code, which must be documented and assigned alongside M24.7.

• Rheumatoid arthritis (RA): Inflammatory destruction of the acetabular rim is a well-recognized route to secondary protrusio. Assign the appropriate M05 or M06 code alongside M24.7.
• Paget’s disease of bone: Abnormal bone remodeling weakens the acetabulum and allows medial protrusion. ICD-10 code M88 covers Paget’s disease.
• Osteomalacia: Softening of bone from vitamin D deficiency or a phosphate disorder compromises acetabular integrity. Assign M83 for adult osteomalacia as applicable.
• Trauma: Acetabular fractures or repeated micro-trauma can produce progressive protrusion over time. Pelvic fractures such as S32.311G are coded from the injury chapter instead.
• Marfan syndrome: Connective tissue laxity is associated with both primary and secondary presentations.

Signs and symptoms

Clinical presentation drives the documentation. The note has to support M24.7 with objective findings, not a radiology impression alone.

• Hip pain, typically groin-deep and worse with weight-bearing
• Restricted range of motion, particularly internal rotation and abduction
• Gait abnormality or antalgic limp
• Progressive functional limitation in severe cases

Synonyms and index terms

The ICD-10-CM alphabetic index maps several clinical terms to M24.7. Physician notes and orthopedic referrals often use one of these instead of the code description.

• Acetabular protrusion
• Hip socket protrusion
• Medial protrusion of the acetabulum
• Intrapelvic protrusion of acetabulum
• Otto pelvis, an older eponym still appearing in legacy notes

None of these terms needs a different code. They all map to M24.7 in the index. When a note uses an eponym like Otto pelvis, confirm the clinical context matches protrusio before assigning, rather than coding from the synonym alone.

Coding guidelines and sequencing

Protrusio acetabuli follows the standard musculoskeletal sequencing rules in the ICD-10-CM Official Guidelines for Coding and Reporting, published each year by CMS and NCHS. Whether M24.7 is first-listed or additional depends on the reason for the encounter.

M24.7 needs no seventh character either, unlike trauma codes such as S52.355J. Coders working in practice management software with built-in code search can check sequencing as they assign.

Documentation requirement: The physician or qualified provider must confirm the diagnosis in the note. Coders cannot assign M24.7 from imaging findings alone, without a clinical interpretation statement in the record.

Related codes used alongside M24.7

M24.7 is rarely the only code on the claim. It usually travels with the underlying cause, the presenting symptom, or a related joint condition. The table below covers the companion codes that come up most often.

Billing and MS-DRG mapping

On inpatient claims, M24.7 groups to the general musculoskeletal MS-DRGs 564, 565, and 566. Which one applies depends on whether the record documents a complication or comorbidity, and whether it is major. A procedure changes the picture entirely, so an ICD-10-PCS code for hip replacement moves the stay into a joint replacement group.

Practice management software like Pabau links diagnosis codes straight to the billing workflow through claims management software. That removes the manual step of cross-referencing grouper tables after the clinical note is finalized.

Payer rules vary. Medicare fee-for-service and commercial payers can apply different medical necessity criteria for procedures performed in the context of M24.7. Check the payer’s Local Coverage Determination before submitting claims for hip arthroplasty or an open reduction with M24.7 as the primary diagnosis.

ICD-10-CM is the US adaptation of the WHO’s ICD. Practices billing internationally should confirm the condition maps to an equivalent code in the local adaptation.

How Pabau supports diagnostic coding workflows

ICD-10 coding usually breaks down at the handoff. A clinician finishes a hip assessment, opens a browser tab to look up M24.7, then retypes it into a separate billing field. Every one of those steps invites a transcription error, and each one delays submission.

Hip diagnoses travel across musculoskeletal specialties, so an osteopathy practice software record and a physical therapy EMR both need code search built in. Pabau puts that search inside the clinical note itself.

Clinicians working in structured client records can search by condition name or code, select M24.7, and populate the claim without leaving the record. Patients with comorbidities need several codes, and those can be assigned and sequenced in the same place.

Digital intake forms can capture the pain, gait, and mobility detail that a musculoskeletal code needs, before the patient arrives. That gives you objective findings to point to when a payer asks what supported M24.7.

Assign ICD-10 codes without leaving the record

Pabau lets clinicians search and assign ICD-10 codes, including M24.7, inside the patient record. Clean documentation flows straight into billing, so claims leave with every code intact.

Book a demo

Conclusion

M24.7 is an easy code to assign and an easy one to under-document. The code selection is settled the moment the diagnosis is confirmed, so the work sits in the note behind it.

Before you submit, check that the record names the etiology, the affected hip, and the objective findings. Get those three in place and the claim survives review without a provider query or an appeal.

Pabau connects that documentation to the claim, so M24.7 and its companion codes land correctly the first time. Book a demo to see how diagnostic coding works inside the patient record.

Continue your research

Screening the hip before you code? Klisic test gives you an exam finding to record alongside the diagnosis.

Need the seventh-character rules in one place? S42.009B shows how encounter type changes the code you submit.

Pairing a diagnosis with a surgical code? 21812 explains what an operative report has to say to support fixation billing.

Recording range of motion before you code? Cervical rotation lateral flexion test is a ready-made form for objective findings.

Wondering how long the notes have to stay on file? How long to keep medical records covers retention by state and record type.

Frequently asked questions