M90.632 vs M90.639

Summary

What is different?

Title wording.The titles differ in one word, “left” (M90.632) versus “unspecified” (M90.639): M90.632 is “Osteitis deformans in neoplastic diseases, left forearm”; M90.639 is “Osteitis deformans in neoplastic diseases, unspecified forearm”.

Registry fact

Can these codes be reported together?

One side per condition.M90.632 and M90.639 name the same condition on opposite sides of the body. Same category and title, differing only in which side is affected — the documentation decides which one applies, and a bilateral code is reported only where the code set provides one.

MedCoder-derivedGuide: Laterality coding

Is there an Excludes1 relationship?

None.Neither entry carries an Excludes1 note that names the other code. M90.632 carries 11 Excludes1 notes and M90.639 carries 11 Excludes1 notes covering other codes; the side-by-side table quotes them.

Official rule

Is there an Excludes2 relationship?

None.Neither entry carries an Excludes2 note that names the other code.

Official rule

Is one more specific?

Yes.M90.632’s title names the condition; M90.639’s title is the unspecified form (“Osteitis deformans in neoplastic diseases, unspecified forearm”).

MedCoder-derivedGuide: Other vs unspecified (NEC vs NOS)

Is one a parent or header code?

No.Both are billable codes, and neither contains the other.

Registry fact

Are there sequencing instructions?

None.Neither entry carries a Code First or Use Additional Code note that names the other.

Official rule

Are there other coding relationships?

Yes.Same condition, opposite side. M90.632 and M90.639 name the same condition on opposite sides of the body.

MedCoder-derivedGuide: Laterality coding

Official rule: a tabular instructional note or a section of the ICD-10-CM Official Guidelines, quoted as published. Registry fact: the codes’ own published attributes (titles, billable status, position in the hierarchy, code set). MedCoder-derived: a reading MedCoder computes from those facts; it is not itself a rule. How to read the labels

Can these codes be reported together?

Official guidance behind these answers

• Section I.B.13 — Laterality · applies to: Laterality

  Some ICD-10-CM codes indicate laterality, specifying whether the condition occurs on the left, right or is bilateral. If no bilateral code is provided and the condition is bilateral, assign separate codes for both the left and right side. If the side is not identified in the medical record, assign the code for the unspecified side. When a patient has a bilateral condition and each side is treated during separate encounters, assign the "bilateral" code (as the condition still exists on both sides), including for the encounter to treat the first side. For the second encounter for treatment after one side has previously been treated and the condition no longer exists on that side, assign the appropriate unilateral code for the side where the condition still exists (e.g., cataract surgery performed on each eye in separate encounters). The bilateral code would not be assigned for the subsequent encounter, as the patient no longer has the condition in the previously-treated site. If the treatment on the first side did not completely resolve the condition, then the bilateral code would still be appropriate. When laterality is not documented by the patient’s provider, code assignment for the affected side may be based on medical record documentation from other clinicians. If there is conflicting medical record documentation regarding the affected side, the patient’s provider should be queried for clarification. […]

  ICD-10-CM Official Guidelines FY2026

Quoted from the ICD-10-CM Official Guidelines for Coding and Reporting in effect for the release shown. The tabular notes above are the code-level instruction; these sections are the convention that says how such a note is applied. Source document (CMS PDF) · Release and checksum

Side by side

Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on.