M84.16 ICD-10-CA code: Nonunion of fracture [pseudarthrosis], lower leg

M84.16 is the ICD-10-CA code for “Nonunion of fracture [pseudarthrosis], lower leg” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.

Official description

M84.16

Nonunion of fracture [pseudarthrosis], lower leg

Short description: Nonunion fx [pseudarthrosis] lower leg

ICD-10-CA · Canada · Also written M8416

Notes for M84.16

As CIHI prints them, with any note M84.16 takes from the headings above it.

Excludes

Conditions classified elsewhere.

Pseudarthrosis after fusion or arthrodesis (M96.0)From M84.1 Nonunion of fracture [pseudarthrosis]
Certain:• conditions originating in the perinatal period (P00-P96)• disorders of the temporomandibular joint (K07.6)• infectious and parasitic diseases (A00-B99)compartment syndrome (T79.6)complications of pregnancy, childbirth and the puerperium (O00-O99)congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)endocrine, nutritional and metabolic diseases (E00-E90)injury, poisoning and certain other consequences of external causes (S00-T98)neoplasms (C00-D48)symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)From Chapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)

Note

[To review the anatomical site captured in the 5th character subclassification see Chapter XIII]From M84.1 Nonunion of fracture [pseudarthrosis]
The following fifth characters represent the following sites of involvement:0 Multiple sites1 Shoulder region: clavical , scapula — joint acromioclavicular, glenohumeral, sternoclavicular2 Upper arm: humerus — elbow joint,3 Forearm: radius , ulna — wrist joint,4 Hand: carpus, fingers, metacarpus — joints between these bones,5 Pelvic region and thigh: buttock , femur , pelvis — joint hip , sacroiliac6 Lower leg: fibula , tibia — knee joint7 Ankle and foot: metatarsus, tarsus, toes — other joints in foot8 Other:head neck ribs skull trunk vertebral column9 Site unspecifiedFrom Chapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)

Where M84.16 sits

1ChapterChapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)
2Block M80-M94Osteopathies and chondropathies
3Block M80-M85Disorders of bone density and structure
4Category M84Disorders of continuity of bone
5Subcategory M84.1Nonunion of fracture [pseudarthrosis]
6Valid code M84.16Nonunion of fracture [pseudarthrosis], lower leg

Source and release

Data release: ICD-10-CA · FY 2026–2027
Effective date: Apr 1, 2026
Publisher: CIHI

This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.

See M84.16 in the CIHI source

Frequently asked questions

What does ICD-10-CA code M84.16 mean?

M84.16 is the ICD-10-CA code for “Nonunion of fracture [pseudarthrosis], lower leg” in CIHI’s ICD-10-CA FY 2026–2027 release.

Where is M84.16 in ICD-10-CA?

M84.16 sits under M84.1 Nonunion of fracture [pseudarthrosis], within M84 Disorders of continuity of bone, within M80-M85 Disorders of bone density and structure, within M80-M94 Osteopathies and chondropathies, within Chapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99).

What coding notes apply to M84.16?

ICD-10-CA lists Note, Excludes notes for M84.16, including those from the headings it sits under. They are listed on this page with where each one comes from.

Which ICD-10-CA release does this page use?

It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.

View M84.1