M88.86 ICD-10-CM Code: Osteitis deformans of lower leg
Compare with another codeCheck this code on a claim
Billing Status: NO. This is a non-billable ICD-10-CM code: report a more specific billable code beneath it.
Coding at a Glance
- Tabular directives
- 2 Excludes1
Not billable · FY2027A non-billable heading in the tabular list: report a more specific code beneath it.
What you need to know
Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too; the Instructions section marks which is which.
Most relevant related codes MedCoder-derived
Read off the official notes above and this code’s own position in the tabular list. Which to report is a documentation question; Compare shows the two side by side.
Coding instructions
Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for M88.86 in the official ICD-10-CM tabular list, quoted as published.
Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026
Trace:FY2027 changesChange historyRelease, file and checksum
Notes without a marker are published on M88.86 itself; “inherited from” names the category or block whose note applies here.
Excludes1 — Not Coded Here
Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
- osteitis deformans in neoplastic disease (M90.6) inherited from M88Compare M88.86 vs M90.6 →
- postprocedural osteopathies (M96.-) inherited from M86-M90Compare M88.86 vs M96 →
Coder workflow for M88.86
MedCoder structured workflow — derived from this code’s own official record
Before you code M88.86
- M88.86 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).
ReviewM88.861, M88.862, M88.869
See the relationships section · Guide: How to choose an ICD-10-CM code →
- Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with M88.86. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).
Choose the right path
- Does the documentation support one of the more specific codes beneath M88.86?
Yes → Select that code and continue the checks below on its own page.
No → M88.86 cannot be reported as written; query for the specificity its subcategory needs. - Does the documentation support a condition named in M88.86’s Excludes1 note?
Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
No → Continue.
Consider M88.86. Then confirm the code is valid for the date of service in the Verify section.
Documentation check
- The provider’s diagnostic statement
- Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Official instructions as workflow
Excludes1 — check before selecting M88.86(2 notes)
Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with M88.86: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.
See the official tabular notes · Guidelines I.A.12.a
Coding decision scenarios
Pattern scenarios for this code’s structure — decision rules, not clinical cases
Documentation: Both the condition M88.86 describes and a condition named in its Excludes1 note are documented for the same encounter.
Coding question: Can both codes be reported?
Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.
Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).
Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.
Coding context
The comparisons, hierarchy, index entries, guidelines, relationships, risk-adjustment and coverage context a coder commonly needs. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.
Code Overview
MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.
Verify Before Coding
From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.
Relationships & Classification
MedCoder-derived relationships — computed from published CMS and AHRQ datasets
Other codes that name M88.86 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.
Referenced by 2 Excludes1 notes: M43 — Other deforming dorsopathies (via M88.-), M90.6 — Osteitis deformans in neoplastic diseases (via M88.-).
These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.
Related Codes
Same Index main term, other category
The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Paget's disease”; these codes share that main term but sit in a different category of the Tabular List.
C21.0 — Malignant neoplasm of anus, unspecified (extramammary, anus), C44.590 — Other specified malignant neoplasm of anal skin (extramammary, anus, skin), C50.01 — Malignant neoplasm of nipple and areola, female (breast), C50.02 — Malignant neoplasm of nipple and areola, male (breast, male)
Contextual Map
Every relationship of M88.86 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.
Run M88.86 with these 2 related codes in Claim Check
Hierarchy
- M00-M99 — Chapter 13: Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) (M00-M99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- M86-M90 — Other osteopathies[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
Referenced by Excludes1 notes
- M43 — Other deforming dorsopathies[Excludes1](via M88.-): “spinal curvature in Paget's disease of bone [osteitis deformans] (M88.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2027
- M90.6 — Osteitis deformans in neoplastic diseases[Excludes1](via M88.-): “osteitis deformans [Paget's disease of bone] (M88.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2027
Nearest codes (34)
- M88 — Osteitis deformans [Paget's disease of bone][Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- M88.0 — Osteitis deformans of skull[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- M88.1 — Osteitis deformans of vertebrae[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- M88.8 — Osteitis deformans of other bones[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- M88.81 — Osteitis deformans of shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- M88.811 — Osteitis deformans of right shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- M88.812 — Osteitis deformans of left shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- M88.819 — Osteitis deformans of unspecified shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- and 26 more
Change history
- FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016
Deep reference
Published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.
Common coding questions
MedCoder editorial
Can M88.86 be billed directly?
No. M88.86 (Osteitis deformans of lower leg) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.
Sources for this page
Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.
- Code, title, tabular notes and index terms Official source data
- CMS/CDC ICD-10-CM FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
- Claim edits Official source data
- CMS Definitions of Medicare Code Edits — v44.0 (October 2026) Release, file and checksum · Publisher’s page
- Change history and date-of-service validity Official source data
- CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
- Comparisons, relationships and the contextual map MedCoder-derived relationship
- Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
- Summary and FAQ answers MedCoder editorial explanation
- Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.
Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 20, 2026 · All releases and sources
Labels on this page: Official source data · MedCoder-derived relationship · MedCoder editorial explanation. How to read the labels · All data sources and release dates · CMS coding rules
Cite this page
Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.
MedCoder.ai. "M88.86 — Osteitis deformans of lower leg." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/m88.86-osteitis-deformans-of-lower-leg
Change history
- FY2016 — October 1, 2015In the code set at ICD-10-CM adoptionOsteitis deformans of lower leg
No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, and none are recorded for this code. Note changes are tracked from FY2027 only.
Nearest Codes in This Family
Official ICD-10-CM classifications closest to M88.86 in its code family, with their registry titles.
- M88.849 — Osteitis deformans of unspecified hand
- M88.85 — Osteitis deformans of thigh
- M88.851 — Osteitis deformans of right thigh
- M88.852 — Osteitis deformans of left thigh
- M88.859 — Osteitis deformans of unspecified thigh
- M88.861 — Osteitis deformans of right lower leg
- M88.862 — Osteitis deformans of left lower leg
- M88.869 — Osteitis deformans of unspecified lower leg
- M88.87 — Osteitis deformans of ankle and foot
- M88.871 — Osteitis deformans of right ankle and foot