ICD-10-CM · Spine

M99.64

M99.64 identifies osseous and subluxation-driven narrowing of the intervertebral foramina specifically at the sacral spinal region, classified as a biomechanical lesion under Chapter 13.

Verified May 8, 2026 · 6 sources ↓

Status: Billable
Chapter: 13
Related CPT: 11
Region: Spine

Drawn from CDCICD10DataAAPCCMSOpsc

Documentation tips

What should appear in the chart to support M99.64.

Source · Editorial brief grounded in 6 cited references ↓

Specify 'sacral region' explicitly in the clinical note — the sacrococcygeal and sacroiliac variants both map here, so name the involved foramen level.
Document the etiology as osseous (e.g., osteophyte, bone hypertrophy) or subluxation-mediated narrowing; 'disc' or 'connective tissue' stenosis routes to M99.74, not M99.64.
Record imaging findings that support foraminal narrowing — CT or MRI evidence of bony encroachment, facet hypertrophy, or subluxation-related foraminal reduction strengthens medical necessity.
If lumbar foramina are also involved, document each level separately so M99.63 can be added alongside M99.64.
For Medicare chiropractic claims, pair M99.64 with a primary M99.04 (segmental and somatic dysfunction of sacral region) per LCD requirements; M99.64 alone may not satisfy medical necessity criteria for manipulation.

Related CPT procedures

Procedure codes commonly billed with M99.64. Linking the right diagnosis to the right procedure is what establishes medical necessity.

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

98940 $26.72

Chiropractic manipulative treatment of one or two spinal regions in a single visit, used when the chiropractor adjusts a limited area such as the cervical or lumbar spine.

98941 $38.41

Chiropractic manipulative treatment of three or four spinal regions during one encounter, the most common level when neck, mid back, and low back are adjusted together.

98942 $49.77

Chiropractic manipulative treatment of all five spinal regions in one visit: cervical, thoracic, lumbar, sacral, and pelvic.

98943 $26.39

Chiropractic manipulation of one or more regions outside the spine, such as the shoulder, elbow, wrist, hip, knee, ankle, ribs, or jaw.

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.

72195 $227.46

MRI of the pelvis performed without contrast material, producing soft-tissue images of pelvic structures without intravenous dye administration.

72200 $33.73

Plain radiographs of the sacroiliac joints taken in fewer than three views, typically to look for arthritis, sacroiliitis, or fracture.

72202 $38.75

Sacroiliac joint radiographs taken in three or more views, usually including angled or oblique projections of both joints.

72220 $32.06

Radiographs of the sacrum and coccyx, with at least two views, to evaluate tailbone pain, fracture, or alignment.

99213 $95.19

Established patient office or outpatient visit requiring 20–29 minutes of total time or low-complexity medical decision-making.

99214 $135.61

Office visit for an established patient requiring moderate-complexity medical decision making (MDM), or 30–39 minutes of total provider time on the date of service.

Common coding pitfalls

The recurring mistakes coders make with M99.64 and adjacent codes.

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

Assigning M99.64 when the stenosis is disc- or connective tissue-driven — those cases require M99.74 (connective tissue and disc stenosis of intervertebral foramina, sacral region), not M99.64.
Using the parent code M99.6 instead of the billable child code M99.64 — M99.6 is a category header and will be rejected as non-specific.
Conflating foraminal stenosis (M99.64) with neural canal (central) stenosis — sacral osseous neural canal stenosis is M99.34, a distinct code.
Failing to add a primary M99.04 code for Medicare chiropractic claims, which can trigger medical necessity denials when M99.64 appears as the sole diagnosis.
Coding M99.64 for lumbar foraminal stenosis — lumbar region maps to M99.63; sacral region is specifically the S1–S5 segment.

Clinical context

Source · Editorial summary grounded in 6 cited references ↓

M99.64 applies when bony overgrowth, osteophyte formation, or vertebral subluxation mechanically reduces the diameter of the sacral intervertebral foramina, compressing exiting nerve roots. The stenosis must be attributed to osseous or subluxation etiology — not connective tissue or disc encroachment, which fall under M99.74. This code is used most often in chiropractic, osteopathic, and interventional spine settings where biomechanical lesions are the primary diagnosis framework.

Note the ICD-10-CM index cross-references: sacrococcygeal and sacroiliac foraminal stenosis of osseous/subluxation type both index to M99.64, so a documented sacroiliac foramen involvement with this etiology lands here, not in a separate pelvic code. If the stenosis is multilevel or spans the lumbar region as well, code M99.63 separately — there is no combined lumbosacral code in the M99.6 subcategory.

M99.64 falls under the M99 'Biomechanical lesions, not elsewhere classified' block, which means it should not be used when the condition is more precisely captured by a structural pathology code (e.g., spondylosis with radiculopathy M47.2x, or spinal stenosis M48.0x). Reserve M99.64 for presentations where the clinical framing is biomechanical — typically chiropractic or OMT encounters — and payer LCDs for those specialties often require an M99.0x segmental dysfunction code listed first, with M99.64 as a supporting diagnosis.

Sibling codes

Other billable codes under M99.6 (laterality / anatomic variants).

M99.67

Osseous and sublux stenosis of intvrt foramina of up extrem

M99.60

Osseous and sublux stenosis of intvrt foramin of head region

M99.62

Osseous and sublux stenos of intvrt foramin of thor region

M99.68

Osseous and sublux stenosis of intvrt foramina of rib cage

M99.65

Osseous and sublux stenos of intvrt foramin of pelvic region

M99.69

Osseous & sublux stenos of intvrt foramin of abd and oth rgn

M99.61

Osseous and sublux stenosis of intvrt foramin of cerv region

M99.63

Osseous and sublux stenos of intvrt foramin of lumbar region

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 6 cited references ↓

01What is the difference between M99.64 and M99.74?

M99.64 is osseous and subluxation stenosis of the sacral intervertebral foramina — the narrowing is caused by bone or vertebral misalignment. M99.74 is connective tissue and disc stenosis of the same foramina — soft tissue or disc material is the cause. Document the etiology clearly to avoid miscoding between these two.

02Does M99.64 cover sacroiliac and sacrococcygeal foraminal stenosis?

Yes. The ICD-10-CM index cross-references both sacroiliac and sacrococcygeal osseous/subluxation foraminal stenosis to M99.64. All three locations (sacral, sacroiliac, sacrococcygeal) share this single code.

03Can M99.64 be used as a standalone diagnosis for Medicare chiropractic billing?

Generally no. Medicare chiropractic LCDs typically require a primary subluxation diagnosis (M99.04 for sacral region segmental dysfunction) with M99.64 as a secondary supporting code. Submitting M99.64 alone may result in a medical necessity denial.

04Should I use M99.64 or M48.08 for sacral spinal stenosis?

M48.08 (spinal stenosis, sacral and sacrococcygeal region) is the structural pathology code used in spine surgery and pain management settings. M99.64 is a biomechanical lesion code used primarily in chiropractic and OMT contexts. If the provider is framing the condition as a structural stenosis rather than a biomechanical lesion, M48.08 is the more appropriate code.

05Is lumbar foraminal stenosis included in M99.64?

No. Lumbar osseous and subluxation foraminal stenosis is M99.63. M99.64 is strictly the sacral region (S1–S5). If both lumbar and sacral foramina are involved, assign both M99.63 and M99.64.

06What imaging documentation supports M99.64?

CT or MRI findings showing bony encroachment on sacral foramina, facet joint hypertrophy, osteophyte formation, or subluxation-related foraminal reduction all support this code. Document specific findings — Kellgren-Lawrence grade is not applicable here, but describing the degree of foraminal narrowing and nerve root involvement strengthens medical necessity.

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)
02
icd10data.com
https://www.icd10data.com/ICD10CM/Codes/M00-M99/M99-M99/M99-/M99.64
03
aapc.com
https://www.aapc.com/codes/icd-10-codes/M99.64
04
cms.gov
https://www.cms.gov/files/document/fy-2025-icd-10-cm-coding-guidelines.pdf
05
cms.gov
https://www.cms.gov/medicare/coding/icd10/downloads/icd10clinicalconceptsorthopedics1.pdf
06
opsc.org
https://www.opsc.org/page/ICD-10

Mira Scribe

Mira AI Scribe captures the affected spinal region (sacral), the stenosis mechanism (osseous vs. subluxation vs. disc), any imaging confirmation of foraminal narrowing (CT/MRI findings, bony overgrowth, subluxation), and associated radicular symptoms. This prevents miscoding to the neural canal stenosis codes (M99.34) or the wrong etiology subcategory (M99.74), both of which can generate claim rejections or audit flags.

See how Mira captures M99.64 documentation