Stenosis of the intervertebral foramina in the pelvic region caused by osseous (bony) changes or subluxation of adjacent spinal or pelvic joint structures, classified as a biomechanical lesion.
Verified May 8, 2026 · 3 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 10
- Region
- Spine
Documentation tips
What should appear in the chart to support M99.65.
Source · Editorial brief grounded in 3 cited references ↓
- Specify the anatomical region as 'pelvic' in the clinical note — do not rely on 'lower back' or generic spine language, which maps to lumbar (M99.63), not pelvic (M99.65).
- Document the mechanism of stenosis: osseous (bony spurring, osteophyte formation) or subluxation of the sacroiliac or lumbosacral joint — this distinguishes M99.65 from M99.75 (connective tissue/disc etiology).
- Record imaging findings that confirm foraminal narrowing in the pelvic region: CT or MRI report noting bony encroachment, facet hypertrophy, or subluxation at the S1/sacropelvic level.
- If radiculopathy or neurological symptoms are present, code those separately — M99.65 captures the structural stenosis, not the functional deficit.
- Note prior conservative care (manipulation, physical therapy, epidural injections) if the encounter relates to escalating treatment, as payers often require a documented treatment progression.
Related CPT procedures
Procedure codes commonly billed with M99.65. Linking the right diagnosis to the right procedure is what establishes medical necessity.
Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis
Common coding pitfalls
The recurring mistakes coders make with M99.65 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Confusing pelvic region (M99.65) with sacral region (M99.64) — the tabular list distinguishes them; verify the treating provider has documented the correct anatomical level.
- Using M99.65 when stenosis is caused by disc herniation or ligamentous hypertrophy — that mechanism maps to M99.75 (connective tissue and disc stenosis, pelvic region), not M99.65.
- Defaulting to a lumbar foraminal stenosis code (M99.63 or M48.06x) when the documented region is the pelvis/sacroiliac level — read the imaging report for level specificity.
- Omitting a radiculopathy or neurological deficit code when lower extremity or pelvic neurological symptoms are documented — M99.65 does not capture those manifestations.
Clinical context
Source · Editorial summary grounded in 3 cited references ↓
M99.65 applies when foraminal narrowing at the pelvic region level is attributed to bony overgrowth, osteophyte encroachment, or joint subluxation — not disc herniation or connective tissue changes. The pelvic region, per the M99 category, refers to the sacroiliac and lumbosacral articulations along with the associated foramina at that level. This distinguishes it from M99.64 (sacral region) and M99.63 (lumbar region); select the code that matches the documented anatomical region of stenosis.
This code sits within the M99 'Biomechanical Lesions, Not Elsewhere Classified' category, which is commonly used by chiropractors, physiatrists, and spine specialists. It is distinct from M99.75 (connective tissue and disc stenosis, pelvic region) — the mechanism matters. If the stenosis is secondary to disc material or ligamentous hypertrophy, M99.75 is the correct sibling code. Document the specific mechanism (osseous vs. subluxation) to support M99.65 over its connective-tissue counterpart.
Because M99 codes represent biomechanical diagnoses, they are frequently used alongside manipulation therapy or non-surgical spinal procedures. Payers may require supporting imaging (CT or MRI demonstrating foraminal narrowing with bony or subluxation etiology) and clinical correlation with radicular or referred pelvic symptoms before reimbursing high-cost interventions. Always pair with any relevant radiculopathy or neurological deficit code if documented.
Sibling codes
Other billable codes under M99.6 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 3 cited references ↓
01What distinguishes M99.65 from M99.64 (sacral region)?
02When should I use M99.75 instead of M99.65?
03Is M99.65 valid for orthopedic and chiropractic billing?
04Do I need to code radiculopathy separately if the patient has leg pain?
05Does M99.65 require a seventh character?
06Can M99.65 be used alongside a spinal stenosis code such as M48.06x?
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)
- 02icd10data.comhttps://www.icd10data.com/ICD10CM/Codes/M00-M99/M99-M99/M99-/M99.65
- 03aapc.comhttps://www.aapc.com/codes/icd-10-codes/M99.65
Mira AI Scribe
Mira AI Scribe captures the treating provider's documented anatomical region (pelvic vs. sacral vs. lumbar), the stated mechanism (osseous/bony vs. subluxation vs. disc/connective tissue), and any imaging findings confirming foraminal narrowing at the pelvic level. This prevents misassignment to M99.64 (sacral) or M99.75 (connective tissue etiology) and avoids the audit risk of an unspecified or region-mismatched biomechanical lesion code.
See how Mira captures M99.65 documentation