Adult osteomalacia with no documented etiology or subtype — use when the provider diagnosis of osteomalacia is confirmed but the underlying cause has not been specified in the medical record.
Verified May 8, 2026 · 4 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 6
- Region
- General
Documentation tips
What should appear in the chart to support M83.9.
Source · Editorial brief grounded in 4 cited references ↓
- Provider must explicitly state 'adult osteomalacia' — do not infer from lab values (low 25-OH vitamin D, elevated ALP) alone without a confirmed diagnosis.
- If an etiology is known, document it by name (malabsorption, malnutrition, drug-induced, senility, postpartum) so a more specific M83.x subcode can be assigned instead of M83.9.
- For Vitamin D assay claims pairing M83.9 with CPT 82652, the chart must support tumor-induced osteomalacia (oncogenic osteomalacia) per CMS Article A57718 asterisk restriction.
- Document any imaging findings (pseudofractures/Looser zones on plain film, low bone density on DXA) that corroborate the diagnosis and support medical necessity for workup orders.
- If the patient has chronic kidney disease or renal insufficiency, evaluate whether renal osteodystrophy (N25.0) is more accurate — the Excludes1 note prohibits coding both.
Related CPT procedures
Procedure codes commonly billed with M83.9. 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 M83.9 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Using M83.9 when the chart documents a specific cause — malabsorption, malnutrition, or drug use — bypasses the more precise M83.2, M83.3, or M83.5 codes and will often fail payer specificity edits.
- Assigning M83.9 alongside E55.0 (rickets, active) or E83.31 (vitamin D-resistant osteomalacia) violates the Excludes1 rule at the M83 category level; only one set applies.
- Linking M83.9 to CPT 82652 without documenting tumor-induced osteomalacia — CMS Article A57718 explicitly restricts this pairing, and claims will deny without that clinical indication.
- Confusing M83.9 (adult osteomalacia, unspecified etiology) with M83.8 (other adult osteomalacia) — M83.8 is for documented but atypical forms not covered by M83.0–M83.5; M83.9 is for truly unspecified etiology.
Clinical context
Source · Editorial summary grounded in 4 cited references ↓
M83.9 is the catch-all code for adult osteomalacia when the chart does not document a specific cause. The M83 category carries six more-specific subcodes — M83.0 (puerperal), M83.1 (senile), M83.2 (due to malabsorption), M83.3 (due to malnutrition), M83.4 (aluminum bone disease), and M83.5 (drug-induced) — so M83.9 is appropriate only after those are ruled out or undocumented. If the provider has identified a cause, code the specific subtype; using M83.9 when a cause is documented is a specificity failure that can trigger payer queries.
M83.9 is Excludes1-restricted at the category level: do not use it for infantile or juvenile osteomalacia (E55.0), renal osteodystrophy (N25.0), active rickets (E55.0), rickets sequelae (E64.3), vitamin D-resistant osteomalacia (E83.31), or vitamin D-resistant rickets (E83.31). These are mutually exclusive — if any apply, the M83.x code is wrong entirely.
CMS LCD policy for Vitamin D Assay Testing (CMS Article A57718) lists M83.9 as a covered diagnosis for both CPT 82306 (25-OH vitamin D) and CPT 82652 (1,25-dihydroxy vitamin D). For CPT 82652, CMS annotates M83.9 with an asterisk: 'Use only for tumor-induced osteomalacia.' Confirm clinical context before linking M83.9 to 82652 to avoid claim denial. MS-DRG grouping: 553 (Bone diseases and arthropathies with MCC) and 554 (without MCC).
Sibling codes
Other billable codes under M83 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 4 cited references ↓
01When should I use M83.9 instead of a more specific M83 subcode?
02Can M83.9 be used for a patient with vitamin D deficiency (E55.9)?
03Does M83.9 support medical necessity for Vitamin D assay testing?
04What MS-DRGs does M83.9 group into?
05Is M83.9 excluded if the patient has renal disease?
06Can M83.9 be assigned for a patient on long-term anticonvulsants with osteomalacia?
07Does M83.9 require a 7th character?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
Mira AI Scribe
Mira AI Scribe captures the provider's diagnosis statement, the absence of a documented cause (malabsorption, malnutrition, medications, renal disease), relevant lab values (25-OH vitamin D, ALP, phosphorus), and any imaging findings (Looser zones, DXA result) to anchor M83.9. This prevents downcoding to a symptom code or an audit flag from using a non-specific code when a specific M83 subtype was actually documented.
See how Mira captures M83.9 documentation