ICD-10-CM M66: Spontaneous rupture of synovium and tendon

ICD-10-CM Diagnosis Code (2025)

Official Description for M66

Spontaneous rupture of synovium and tendon

Coding Notes & Guidelines for M66

Includes Notes

rupture that occurs when a normal force is applied to tissues that are inferred to have less than normal strength

Excludes2: Not Included Here
  • rotator cuff syndrome (M75.1-)
  • rupture where an abnormal force is applied to normal tissue - see injury of tendon by body region
Excludes2: Not Included Here

rupture of popliteal cyst (M66.0)

Inclusion Terms

Rupture of synovial cyst

Inclusion Terms

Rupture at musculotendinous junction, nontraumatic

Child Codes (More Specific Codes for M66):

M66.0 - Rupture of popliteal cyst M66.1 - Rupture of synovium M66.10 - Rupture of synovium, unspecified joint M66.11 - Rupture of synovium, shoulder M66.111 - Rupture of synovium, right shoulder M66.112 - Rupture of synovium, left shoulder M66.119 - Rupture of synovium, unspecified shoulder M66.12 - Rupture of synovium, elbow M66.121 - Rupture of synovium, right elbow M66.122 - Rupture of synovium, left elbow M66.129 - Rupture of synovium, unspecified elbow M66.13 - Rupture of synovium, wrist M66.131 - Rupture of synovium, right wrist M66.132 - Rupture of synovium, left wrist M66.139 - Rupture of synovium, unspecified wrist M66.14 - Rupture of synovium, hand and fingers M66.141 - Rupture of synovium, right hand M66.142 - Rupture of synovium, left hand M66.143 - Rupture of synovium, unspecified hand M66.144 - Rupture of synovium, right finger(s) M66.145 - Rupture of synovium, left finger(s) M66.146 - Rupture of synovium, unspecified finger(s) M66.15 - Rupture of synovium, hip M66.151 - Rupture of synovium, right hip M66.152 - Rupture of synovium, left hip M66.159 - Rupture of synovium, unspecified hip M66.17 - Rupture of synovium, ankle, foot and toes M66.171 - Rupture of synovium, right ankle M66.172 - Rupture of synovium, left ankle M66.173 - Rupture of synovium, unspecified ankle M66.174 - Rupture of synovium, right foot M66.175 - Rupture of synovium, left foot M66.176 - Rupture of synovium, unspecified foot M66.177 - Rupture of synovium, right toe(s) M66.178 - Rupture of synovium, left toe(s) M66.179 - Rupture of synovium, unspecified toe(s) M66.18 - Rupture of synovium, other site M66.2 - Spontaneous rupture of extensor tendons M66.20 - Spontaneous rupture of extensor tendons, unspecified site M66.21 - Spontaneous rupture of extensor tendons, shoulder M66.211 - Spontaneous rupture of extensor tendons, right shoulder M66.212 - Spontaneous rupture of extensor tendons, left shoulder M66.219 - Spontaneous rupture of extensor tendons, unspecified shoulder M66.22 - Spontaneous rupture of extensor tendons, upper arm M66.221 - Spontaneous rupture of extensor tendons, right upper arm M66.222 - Spontaneous rupture of extensor tendons, left upper arm M66.229 - Spontaneous rupture of extensor tendons, unspecified upper arm M66.23 - Spontaneous rupture of extensor tendons, forearm M66.231 - Spontaneous rupture of extensor tendons, right forearm M66.232 - Spontaneous rupture of extensor tendons, left forearm M66.239 - Spontaneous rupture of extensor tendons, unspecified forearm M66.24 - Spontaneous rupture of extensor tendons, hand M66.241 - Spontaneous rupture of extensor tendons, right hand M66.242 - Spontaneous rupture of extensor tendons, left hand M66.249 - Spontaneous rupture of extensor tendons, unspecified hand M66.25 - Spontaneous rupture of extensor tendons, thigh M66.251 - Spontaneous rupture of extensor tendons, right thigh M66.252 - Spontaneous rupture of extensor tendons, left thigh M66.259 - Spontaneous rupture of extensor tendons, unspecified thigh M66.26 - Spontaneous rupture of extensor tendons, lower leg M66.261 - Spontaneous rupture of extensor tendons, right lower leg M66.262 - Spontaneous rupture of extensor tendons, left lower leg M66.269 - Spontaneous rupture of extensor tendons, unspecified lower leg M66.27 - Spontaneous rupture of extensor tendons, ankle and foot M66.271 - Spontaneous rupture of extensor tendons, right ankle and foot M66.272 - Spontaneous rupture of extensor tendons, left ankle and foot M66.279 - Spontaneous rupture of extensor tendons, unspecified ankle and foot M66.28 - Spontaneous rupture of extensor tendons, other site M66.29 - Spontaneous rupture of extensor tendons, multiple sites M66.3 - Spontaneous rupture of flexor tendons M66.30 - Spontaneous rupture of flexor tendons, unspecified site M66.31 - Spontaneous rupture of flexor tendons, shoulder M66.311 - Spontaneous rupture of flexor tendons, right shoulder M66.312 - Spontaneous rupture of flexor tendons, left shoulder M66.319 - Spontaneous rupture of flexor tendons, unspecified shoulder M66.32 - Spontaneous rupture of flexor tendons, upper arm M66.321 - Spontaneous rupture of flexor tendons, right upper arm M66.322 - Spontaneous rupture of flexor tendons, left upper arm M66.329 - Spontaneous rupture of flexor tendons, unspecified upper arm M66.33 - Spontaneous rupture of flexor tendons, forearm M66.331 - Spontaneous rupture of flexor tendons, right forearm M66.332 - Spontaneous rupture of flexor tendons, left forearm M66.339 - Spontaneous rupture of flexor tendons, unspecified forearm M66.34 - Spontaneous rupture of flexor tendons, hand M66.341 - Spontaneous rupture of flexor tendons, right hand M66.342 - Spontaneous rupture of flexor tendons, left hand M66.349 - Spontaneous rupture of flexor tendons, unspecified hand M66.35 - Spontaneous rupture of flexor tendons, thigh M66.351 - Spontaneous rupture of flexor tendons, right thigh M66.352 - Spontaneous rupture of flexor tendons, left thigh M66.359 - Spontaneous rupture of flexor tendons, unspecified thigh M66.36 - Spontaneous rupture of flexor tendons, lower leg M66.361 - Spontaneous rupture of flexor tendons, right lower leg M66.362 - Spontaneous rupture of flexor tendons, left lower leg M66.369 - Spontaneous rupture of flexor tendons, unspecified lower leg M66.37 - Spontaneous rupture of flexor tendons, ankle and foot M66.371 - Spontaneous rupture of flexor tendons, right ankle and foot M66.372 - Spontaneous rupture of flexor tendons, left ankle and foot M66.379 - Spontaneous rupture of flexor tendons, unspecified ankle and foot M66.38 - Spontaneous rupture of flexor tendons, other site M66.39 - Spontaneous rupture of flexor tendons, multiple sites M66.8 - Spontaneous rupture of other tendons M66.80 - Spontaneous rupture of other tendons, unspecified site M66.81 - Spontaneous rupture of other tendons, shoulder M66.811 - Spontaneous rupture of other tendons, right shoulder M66.812 - Spontaneous rupture of other tendons, left shoulder M66.819 - Spontaneous rupture of other tendons, unspecified shoulder M66.82 - Spontaneous rupture of other tendons, upper arm M66.821 - Spontaneous rupture of other tendons, right upper arm M66.822 - Spontaneous rupture of other tendons, left upper arm M66.829 - Spontaneous rupture of other tendons, unspecified upper arm M66.83 - Spontaneous rupture of other tendons, forearm M66.831 - Spontaneous rupture of other tendons, right forearm M66.832 - Spontaneous rupture of other tendons, left forearm M66.839 - Spontaneous rupture of other tendons, unspecified forearm M66.84 - Spontaneous rupture of other tendons, hand M66.841 - Spontaneous rupture of other tendons, right hand M66.842 - Spontaneous rupture of other tendons, left hand M66.849 - Spontaneous rupture of other tendons, unspecified hand M66.85 - Spontaneous rupture of other tendons, thigh M66.851 - Spontaneous rupture of other tendons, right thigh M66.852 - Spontaneous rupture of other tendons, left thigh M66.859 - Spontaneous rupture of other tendons, unspecified thigh M66.86 - Spontaneous rupture of other tendons, lower leg M66.861 - Spontaneous rupture of other tendons, right lower leg M66.862 - Spontaneous rupture of other tendons, left lower leg M66.869 - Spontaneous rupture of other tendons, unspecified lower leg M66.87 - Spontaneous rupture of other tendons, ankle and foot M66.871 - Spontaneous rupture of other tendons, right ankle and foot M66.872 - Spontaneous rupture of other tendons, left ankle and foot M66.879 - Spontaneous rupture of other tendons, unspecified ankle and foot M66.88 - Spontaneous rupture of other tendons, other sites M66.89 - Spontaneous rupture of other tendons, multiple sites M66.9 - Spontaneous rupture of unspecified tendon

About ICD-10-CM Code M66 (Spontaneous rupture of synovium and tendon)

ICD-10-CM code M66 is a billable or specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. The 2025 edition of ICD-10-CM M66 became effective on October 1, 2024.

This page provides detailed information about M66 - Spontaneous rupture of synovium and tendon. It includes common terminology, coding guidelines such as "Includes," "Excludes1," and "Excludes2" notes, and information on required 7th characters. Utilizing this information correctly is essential for accurate medical coding and claims submission for conditions like Spontaneous rupture of synovium and tendon.