M05.9
Rheumatoid arthritis with rheumatoid factor, unspecified
Billable FY2026 2025-10-01 → 2026-09-30
This is the unspecified option. 10 more
specific codes sit alongside it. Worth
checking whether the documentation supports one of them.
Exclusions 13 never code together
M05code
M00-M99chapter
Excludes2
- arthropathic psoriasis (L40.5-)L40.5-
- certain conditions originating in the perinatal period (P04-P96)P04-P96
- certain infectious and parasitic diseases (A00-B99)A00-B99
- compartment syndrome (traumatic) (T79.A-)T79.A-
- complications of pregnancy, childbirth and the puerperium (O00-O9A)O00-O9A
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Q00-Q99
- endocrine, nutritional and metabolic diseases (E00-E88)E00-E88
- injury, poisoning and certain other consequences of external causes (S00-T88)S00-T88
- neoplasms (C00-D49)C00-D49
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)R00-R94
Excludes1 — never code together. The excluded condition and this one are mutually exclusive.
Excludes2 — not included here, but the patient may have both. Code both when documented.
Instructional notes 2
Index entries leading here 1
Alongside this code 10 same parent — M05
M05.0 Felty's syndrome category M05.1 Rheumatoid lung disease with rheumatoid arthritis category M05.2 Rheumatoid vasculitis with rheumatoid arthritis category M05.3 Rheumatoid heart disease with rheumatoid arthritis category M05.4 Rheumatoid myopathy with rheumatoid arthritis category M05.5 Rheumatoid polyneuropathy with rheumatoid arthritis category M05.6 Rheumatoid arthritis w involvement of oth organs and systems category M05.7 Rheumatoid arthritis w rheumatoid factor w/o org/sys involv category M05.8 Other rheumatoid arthritis with rheumatoid factor category M05.A Abn rheu fctr & anti-citrul protein antibody w rheu arthrit
Medications 1
MED-RT files conditions by MeSH, which carves the world differently from ICD-10. These are name matches on this code's description, offered as candidates — not as an assertion that they are this code.
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.