ICD-10-CM · Other

M26.25

M26.25 identifies a dentofacial anomaly in which the vertical or horizontal distance between the maxillary and mandibular dental arches deviates from accepted norms, affecting occlusal relationships and jaw function.

Verified May 8, 2026 · 6 sources ↓

Status: Billable
Chapter: 13
Related CPT: 17
Region: Other

Drawn from CDCICD10DataCMSAAPCFindacode

Documentation tips

What should appear in the chart to support M26.25.

Source · Editorial brief grounded in 6 cited references ↓

Record the specific nature of the interarch distance anomaly — state whether the distance is excessive or insufficient, and whether it affects anterior, posterior, or full-arch relationships.
Include cephalometric or panoramic radiograph findings that quantify the interarch discrepancy (e.g., reduced vertical dimension, increased freeway space) to support medical necessity.
Document functional impact — chewing difficulty, speech impairment, TMJ symptoms, or prosthetic instability — to justify treatment and defend payer scrutiny.
If the anomaly is congenital versus acquired (e.g., secondary to tooth loss or prior orthognathic surgery), note etiology explicitly; it affects clinical context even though M26.25 does not split by etiology.
When multiple arch relationship anomalies coexist (e.g., interarch distance anomaly plus Angle's Class II malocclusion), list all applicable M26.2x codes — do not collapse into M26.29 unless no specific code fits.

Related CPT procedures

Procedure codes commonly billed with M26.25. Linking the right diagnosis to the right procedure is what establishes medical necessity.

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

21085 $710.10

Impression and custom fabrication of an oral surgical splint used to support facial structures during orthognathic or jaw reconstruction surgery.

21100 $630.94

Application of a halo-type external fixation appliance to stabilize the maxillofacial skeleton, with removal reported as a separate procedure.

21141 $1,208.44

Midface reconstruction via LeFort I osteotomy, single-piece maxillary segment moved in any direction, performed without bone graft.

21145 $1,390.81

LeFort I single-piece maxillary osteotomy performed with bone grafting to reposition the upper jaw and correct midface skeletal deformity.

21150 $1,415.20

Reconstruction of the midface via a modified Le Fort II osteotomy pattern that advances the nasal-orbital complex anteriorly without mobilizing the zygoma.

21155 $1,851.41

Reconstruction of the midface using a modified LeFort III osteotomy with internal fixation, repositioning the midface skeleton to correct severe craniofacial deformities.

21160 $2,392.84

Reconstruction of the midface (Le Fort III level) with advancement using an internal distraction device — a high-complexity craniofacial procedure performed for severe midface hypoplasia or retrusion.

21193 $1,108.58

Surgical reconstruction of the mandibular rami (vertical portions of the lower jaw) to correct deformity or dysfunction without the use of bone or tissue grafting material.

21194 $1,279.59

Reconstruction of the mandibular rami using a horizontal, vertical, C, or L osteotomy, with bone graft harvested from the patient (graft procurement included).

21195 $1,217.46

Surgical reconstruction of the mandibular rami and/or body using a sagittal split osteotomy technique, performed without internal rigid fixation hardware.

21196 $1,296.62

Surgical reconstruction of the mandibular body and/or rami using a sagittal split osteotomy technique, with internal fixation applied to stabilize the repositioned jaw segments.

21198 $908.84

Surgical reconstruction of a lower jaw (mandibular) segment, typically involving osteotomy and repositioning or rebuilding of bone to correct deformity from trauma, disease, or congenital origin.

21199 $906.17

Segmental mandibular osteotomy with genioglossus muscle advancement — the lower jaw is cut in segments, repositioned, and the tongue-base muscle attachment is advanced forward.

21089 View procedure details

70486 View procedure details

70487 View procedure details

70488 View procedure details

Common coding pitfalls

The recurring mistakes coders make with M26.25 and adjacent codes.

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

Confusing M26.25 with M26.36/M26.37: those codes capture interocclusal distance anomalies of fully erupted tooth position, not the broader arch-to-arch relationship; review the clinical distinction before assigning.
Defaulting to M26.20 (unspecified anomaly of dental arch relationship) or M26.4 (malocclusion, unspecified) when M26.25 is documented — unspecified codes invite downcoding and medical necessity denials.
Assigning M26.25 for TMJ disorders: temporomandibular joint conditions belong under M26.6x, not M26.2x, even when interarch distance contributes to TMJ loading.
Omitting secondary codes for coexisting arch anomalies (e.g., open bite M26.220, reverse articulation M26.24) when the patient has multiple documented dental arch relationship problems — each billable condition should be coded.
Using M26.25 without supporting imaging or clinical measurement documentation, which exposes the claim to medical necessity denial on audit.

Clinical context

Source · Editorial summary grounded in 6 cited references ↓

M26.25 falls under the M26.2 subcategory (Anomalies of dental arch relationship) within the broader M26 category of dentofacial anomalies including malocclusion. Use it when documentation supports an abnormal interarch distance — excessive or insufficient space between the upper and lower arches — that is not better captured by a more specific sibling code. Clinically, this includes conditions like excessive interocclusal clearance or collapsed vertical dimension that affect bite function, TMJ loading, or prosthetic planning.

This code is most commonly assigned in oral and maxillofacial surgery, orthodontic, or prosthodontic contexts. It may appear as a primary diagnosis driving orthognathic surgical planning or as a secondary diagnosis supporting medical necessity for orthodontic treatment, splint therapy, or oral appliance fabrication. If the anomaly is limited to tooth position rather than arch relationship, look first at M26.36 (insufficient interocclusal distance of fully erupted teeth) or M26.37 (excessive interocclusal distance) before defaulting to M26.25.

Do not use M26.25 for TMJ disorders — those belong under M26.6x. If the interarch distance anomaly is part of a broader malocclusion, code all applicable M26.2x conditions; ICD-10-CM does not restrict multiple codes within this subcategory when clinically warranted.

Sibling codes

Other billable codes under M26.2 (laterality / anatomic variants).

M26.20

Unspecified anomaly of dental arch relationship

M26.24

Reverse articulation

M26.23

Excessive horizontal overlap

M26.29

Other anomalies of dental arch relationship

Frequently asked questions

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

01What is interarch distance, and why does its anomaly get its own ICD-10 code?

Interarch distance is the measured space between the maxillary and mandibular arches, either at rest or in occlusion. Deviations — too much or too little — affect occlusal function, prosthetic fit, and TMJ health enough to warrant distinct clinical classification under M26.25.

02When should I use M26.25 versus M26.36 or M26.37?

M26.36 and M26.37 describe insufficient or excessive interocclusal distance specifically of fully erupted teeth — a tooth-position anomaly under M26.3. M26.25 describes the arch-level relationship anomaly under M26.2. If the problem is at the arch relationship level, use M26.25; if it's a tooth-position issue, use M26.36 or M26.37.

03Can M26.25 be used alongside other M26.2x codes on the same claim?

Yes. ICD-10-CM does not restrict multiple codes within M26.2x. If the patient has a documented interarch distance anomaly plus, for example, Angle's Class II malocclusion (M26.211), assign both. Code the clinically most significant condition first.

04Is M26.25 appropriate for a diagnosis of reduced vertical dimension in a denture patient?

It can be, if the provider documents that the reduced vertical dimension reflects an anomaly of interarch distance affecting arch relationship. Pair it with any applicable Z-code for absence of teeth (Z87.098 or equivalent) and document the functional impact clearly.

05Does M26.25 require a 7th character?

No. M26.25 is a 5-character billable code with no 7th-character extension requirement. It is fully valid as coded; do not add placeholder characters.

06What CPT procedures are most commonly linked to M26.25?

Orthognathic surgical procedures (e.g., LeFort osteotomies, mandibular osteotomies in the 21141–21199 range), oral appliance fabrication (21085, 21089), and maxillofacial imaging (70486–70488) are the most common procedure codes paired with this diagnosis.

07Can an orthopedic or oral maxillofacial surgeon assign M26.25, or is it limited to dentists?

Any qualified provider legally accountable for establishing the diagnosis may assign M26.25 per ICD-10-CM Official Guidelines. Oral and maxillofacial surgeons routinely bill this code when performing orthognathic surgery; orthodontists and prosthodontists use it in non-surgical treatment planning contexts.

Sources & references

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

Mira AI Scribe

The Mira AI Scribe captures the provider's documented interarch distance finding — including whether it is excessive or insufficient, the affected arch region, any cephalometric or radiographic measurements, functional complaints (chewing, speech, TMJ symptoms), and prior treatment history. This prevents claim submission with unspecified fallback codes (M26.20 or M26.4) that trigger payer downcoding and medical necessity flags.

See how Mira captures M26.25 documentation