Adult osteomalacia caused by a drug or medication other than aluminum-containing compounds, resulting in defective bone mineralization in a skeletally mature patient.
Verified May 8, 2026 · 5 sources ↓
- Status
- Billable
- Chapter
- 13
- Related CPT
- 5
- Region
- General
Documentation tips
What should appear in the chart to support M83.5.
Source · Editorial brief grounded in 5 cited references ↓
- Provider must explicitly name the causative drug and document the causal link between the medication and the bone disease — 'osteomalacia secondary to long-term phenytoin use' is sufficient; 'osteomalacia, on phenytoin' is not.
- Always assign the corresponding T36–T50 adverse effect code with a 5th or 6th character of 5 alongside M83.5; omitting it will leave the adverse effect unreported and may trigger a claim edit.
- Document that the patient is a skeletally mature adult — this code is invalid for pediatric or juvenile patients; E55.0 applies to infantile and juvenile osteomalacia.
- Record relevant lab findings supporting the diagnosis: serum 25-OH vitamin D level, serum phosphorus, alkaline phosphatase, and PTH results, as these directly support medical necessity for associated vitamin D assay testing.
- If the patient also has renal disease, confirm the provider is not attributing the bone disease to renal osteodystrophy (N25.0), which is excluded from M83.5 — a provider query may be needed when both conditions coexist.
Related CPT procedures
Procedure codes commonly billed with M83.5. 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 M83.5 and adjacent codes.
Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓
- Omitting the mandatory T36–T50 adverse effect code: the tabular 'Use additional code' instruction is not optional — pairing M83.5 alone is an incomplete code assignment.
- Using M83.5 when the causative drug is an aluminum-containing agent: that scenario maps to M83.4 (aluminum bone disease), not M83.5.
- Assigning M83.5 for pediatric patients or juvenile osteomalacia — this code is adult-only; E55.0 covers infantile and juvenile presentations.
- Confusing M83.5 with vitamin D-resistant osteomalacia (E83.31): if the condition is driven by a genetic or metabolic disorder of vitamin D metabolism rather than a specific drug, E83.31 applies instead.
- Defaulting to M83.9 (adult osteomalacia, unspecified) when the drug cause is documented — M83.5 is the more specific and correct code whenever a non-aluminum drug etiology is established.
Clinical context
Source · Editorial summary grounded in 5 cited references ↓
M83.5 captures drug-induced softening of bone in adults when the causative agent is something other than aluminum (aluminum bone disease is separately classified at M83.4). Common offending drug classes documented in clinical literature include antiepileptics (phenytoin, phenobarbital), antiretrovirals (tenofovir), long-term corticosteroids, antacids with phosphate-binding properties, and certain chemotherapy agents — though the provider must document the causal relationship explicitly.
The tabular instruction is mandatory: you must assign an additional code from T36–T50 with a 5th or 6th character of 5 to identify the adverse effect of the drug. Without that secondary code, the claim is incomplete. Sequence M83.5 first as the manifestation, then the T-code adverse effect.
M83.5 is excluded from use when the correct diagnosis is infantile or juvenile osteomalacia (E55.0), renal osteodystrophy (N25.0), active rickets or its sequelae (E55.0, E64.3), or vitamin D-resistant osteomalacia/rickets (E83.31). CMS LCD policy lists M83.5 as a covered diagnosis supporting medical necessity for vitamin D assay testing (CPT 82306, 82652), which makes accurate coding directly relevant to lab reimbursement.
Sibling codes
Other billable codes under M83 (laterality / anatomic variants).
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 5 cited references ↓
01Do I always need a second code with M83.5?
02Which code goes first — M83.5 or the T-code?
03Can M83.5 be used for a patient on dialysis whose bone disease is linked to medication?
04Does M83.5 support medical necessity for vitamin D lab testing?
05What is the difference between M83.4 and M83.5?
06Can M83.5 be used if the provider documents low vitamin D levels as the mechanism?
07Is M83.5 valid for a patient under 18 years old?
Sources & references
Editorial content was developed using the following public sources. Last verified May 8, 2026.
- 01CDC ICD-10-CM Tabular List 2026 (FY2026, effective October 1, 2025) — M83.5
- 02ICD-10-CM Official Guidelines for Coding and Reporting FY2026, CDC/NCHS — http://stacks.cdc.gov/view/cdc/250974
- 03CMS Medicare Coverage Database Article A57718: Billing and Coding: Vitamin D Assay Testing — https://www.cms.gov/medicare-coverage-database/view/article.aspx?articleid=57718
- 04CMS Medicare Coverage Database Article A56416: Billing and Coding: Assays for Vitamins and Metabolic Function — https://www.cms.gov/medicare-coverage-database/view/article.aspx?articleid=56416
- 05AAPC Codify ICD-10-CM M83.5 — https://www.aapc.com/codes/icd-10-codes/M83.5
Mira AI Scribe
Mira's AI scribe captures the specific implicated medication, the provider's documented causal statement linking that drug to impaired bone mineralization, and supporting lab values (25-OH vitamin D, phosphorus, alkaline phosphatase). This prevents claim submission without the required T36–T50 adverse effect code, avoids downcoding to unspecified M83.9, and preserves the medical necessity documentation needed for covered vitamin D assay testing under CMS LCD policy.
See how Mira captures M83.5 documentation