ICD-10-CM · Hip

M16.0

Idiopathic degenerative joint disease affecting both hips simultaneously, classified as primary (not caused by trauma, dysplasia, or other underlying condition).

Verified May 8, 2026 · 5 sources ↓

Status: Billable
Chapter: 13
Related CPT: 9
Region: Hip

Drawn from CDCCMSicd10data.com 2026ICD

Documentation tips

What should appear in the chart to support M16.0.

Source · Editorial brief grounded in 5 cited references ↓

The provider must explicitly state bilateral involvement — 'osteoarthritis of both hips' or 'bilateral hip OA' — not just findings on a bilateral X-ray series.
Confirm the OA is primary (idiopathic): the note should exclude or not reference trauma history, prior fracture, hip dysplasia, or inflammatory arthritis as a contributing cause.
Radiographic support should document joint space narrowing and/or osteophyte formation in both hips; note the Kellgren-Lawrence grade per side if available.
Document functional limitations (pain with ambulation, reduced ROM, antalgic gait) to support medical necessity for injections, PT, or surgical pre-authorization.
If conservative care has been trialed prior to surgical referral, record the treatments attempted (NSAIDs, PT, injections) and duration — payers require this for THA pre-auth.

Related CPT procedures

Procedure codes commonly billed with M16.0. Linking the right diagnosis to the right procedure is what establishes medical necessity.

Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis

27130 $1,162.02

Primary total hip arthroplasty replacing both the acetabular socket and proximal femoral components with prosthetic implants, with or without bone graft.

27132 $1,504.04

Conversion of a previously operated hip — any prior surgery except total hip arthroplasty — to a complete total hip arthroplasty, replacing both femoral and acetabular components, with or without bone graft.

27134 $1,695.43

Revision of total hip arthroplasty involving replacement of both the femoral and acetabular components in a single operative session.

73521 $41.75

Bilateral hip X-ray examination capturing two radiographic views of both hips, including the pelvis when performed.

73523 $61.46

Radiologic examination of both hips, including the pelvis when performed, requiring a minimum of five views captured from multiple projections.

20610 $68.81

Aspiration and/or injection of a major joint or bursa (shoulder, hip, knee, or subacromial bursa) performed without ultrasound guidance.

27096 $175.69

Injection into the sacroiliac joint with fluoroscopic or CT image guidance, including arthrography when performed.

97110 $29.06

Therapeutic exercise billed per 15-minute unit, targeting strength, endurance, range of motion, or flexibility with direct one-on-one patient contact.

97530 View procedure details

Common coding pitfalls

The recurring mistakes coders make with M16.0 and adjacent codes.

Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓

Using M16.9 (unspecified) or M16.10 (unilateral unspecified) when the note clearly documents bilateral primary OA — always code to the highest specificity documented.
Coding M16.0 when only one hip is addressed in the visit; if the encounter focuses on a single hip, M16.11 or M16.12 may be more appropriate as the first-listed diagnosis.
Applying M16.0 when the bilateral OA has a known secondary cause — post-traumatic OA of both hips is M16.4, not M16.0.
Confusing M16.0 with M15 (polyosteoarthritis) — M15 is for OA involving multiple joint groups; M16.0 is specific to bilateral hip involvement only.
Failing to distinguish primary from secondary OA when a history of hip dysplasia is present — dysplastic bilateral OA requires M16.2.

Clinical context

Source · Editorial summary grounded in 5 cited references ↓

M16.0 is the correct code when the provider documents primary osteoarthritis in both hips. 'Primary' means idiopathic — no prior trauma, developmental dysplasia, or other identifiable secondary cause drives the degeneration. If either hip's OA traces to a known cause, step down to the appropriate secondary code: M16.2 (bilateral dysplastic), M16.4 (bilateral post-traumatic), or M16.6 (other bilateral secondary).

Use M16.0 only when both hips are explicitly documented as affected. If the note describes only one hip — even if the other is mentioned in passing without a confirmed diagnosis — use M16.11 (right) or M16.12 (left). If bilateral involvement is clinically apparent but the provider has not stated it, query before coding; do not infer laterality from imaging alone.

M16.0 is a CMS-recognized diagnosis supporting medical necessity for total hip arthroplasty (CMS Article A57765). It maps to MS-DRG 553/554 (Bone Diseases and Arthropathies with/without MCC). Accurate use of this code versus M16.9 (unspecified) or M16.10 (unspecified unilateral) matters for risk adjustment, pre-authorization, and justifying downstream services including imaging, corticosteroid injections, and physical therapy.

Sibling codes

Other billable codes under M16 (laterality / anatomic variants).

M16.7

Other unilateral secondary osteoarthritis of hip

M16.9

Osteoarthritis of hip, unspecified

M16.4

Bilateral post-traumatic osteoarthritis of hip

M16.6

Other bilateral secondary osteoarthritis of hip

M16.2

Bilateral osteoarthritis resulting from hip dysplasia

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 5 cited references ↓

01Can I use M16.0 if only one hip is being treated surgically this encounter?

Yes, M16.0 can still be listed as the diagnosis if both hips have documented primary OA, even if only one is being operated on. However, some coders list the specific unilateral code (M16.11 or M16.12) as first-listed for the operative hip and M16.0 as a secondary diagnosis — verify payer preference and operative report language.

02What is the difference between M16.0 and M16.9?

M16.0 specifies bilateral primary (idiopathic) OA of the hip. M16.9 is osteoarthritis of hip, unspecified — used only when laterality and type cannot be determined from documentation. Never default to M16.9 when the record supports M16.0.

03Does M16.0 require imaging to be coded?

ICD-10-CM does not mandate imaging as a coding prerequisite, but clinical validation for M16.0 requires radiographic evidence of joint space narrowing and osteophyte formation in both hips. Coding without supporting imaging increases audit risk and can trigger medical necessity denials.

04When should I use M16.2 instead of M16.0?

Use M16.2 (bilateral osteoarthritis resulting from hip dysplasia) when documented developmental dysplasia of the hip is the underlying cause of bilateral OA. M16.0 is reserved for idiopathic (primary) bilateral hip OA with no identifiable structural or traumatic cause.

05Is M16.0 a valid supporting diagnosis for total hip arthroplasty (THA)?

Yes. CMS Article A57765 explicitly lists M16.0 as a diagnosis code that supports medical necessity for major joint replacement of the hip, including total hip arthroplasty (CPT 27130/27132).

06What if the provider documents bilateral hip OA but doesn't specify primary versus secondary?

Query the provider before assigning M16.0. If primary versus secondary status cannot be clarified, M16.9 (unspecified) is the fallback, but this sacrifices specificity and may affect reimbursement and pre-authorization outcomes.

07Can M16.0 be used alongside a unilateral hip code in the same encounter?

No. M16.0 already captures both hips; adding M16.11 or M16.12 in the same encounter for the same condition creates a redundant and potentially conflicting code pair. Use M16.0 alone when bilateral primary OA is the documented diagnosis.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

01CDC ICD-10-CM Tabular List 2026 (effective Oct 1, 2025)
02CMS ICD-10 Clinical Concepts for Orthopedics — https://www.cms.gov/medicare/coding/icd10/downloads/icd10clinicalconceptsorthopedics1.pdf
03CMS Billing and Coding: Major Joint Replacement (Hip and Knee) Article A57765 — https://www.cms.gov/medicare-coverage-database/view/article.aspx?articleid=57765
04icd10data.com 2026 ICD-10-CM M16.0 — https://www.icd10data.com/ICD10CM/Codes/M00-M99/M15-M19/M16-/M16.0
05ICDcodes.ai Bilateral Hip Osteoarthritis Documentation Guide — https://icdcodes.ai/diagnosis/bilateral-hip-osteoarthritis/documentation

Mira AI Scribe

Mira captures bilateral hip pain, provider confirmation that both hips are affected, absence of trauma or dysplasia history, and imaging findings (joint space narrowing, osteophytes per hip) — all elements needed to justify M16.0 over unspecified or unilateral alternatives. This prevents downcoding to M16.9, blocks audit flags for missing laterality documentation, and supports pre-authorization for total hip arthroplasty.

See how Mira captures M16.0 documentation