2027 ICD-10-CM Diagnosis Code M66.0Rupture of popliteal cyst
ICD-10-CM Codes›M00–M99›M65-M67›M66
- Billable — Valid for Submission
- Not Chronic
M66.0 is a billable ICD-10-CM diagnosis code for rupture of popliteal cyst. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 557 through 558. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Tendon and synovial disorders.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Injury of bursa of knee
- Rupture of bursa
- Rupture of popliteal bursa
- Rupture of synovial cyst of knee
- Rupture of synovial cyst of left knee
- Rupture of synovial cyst of right knee
- Rupture of synovial popliteal cyst
- Rupture of synovial popliteal cyst of left knee
- Rupture of synovial popliteal cyst of right knee
- Rupture of synovium - knee
- Synovial cyst of left knee
- Synovial cyst of right knee
- Synovial popliteal cyst
- Synovial popliteal cyst of left knee
- Synovial popliteal cyst of right knee
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to M66.0: its own notes plus those printed at M66 and Chapter 13. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- rupture that occurs when a normal force is applied to tissues that are inferred to have less than normal strength
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- rotator cuff syndrome (M75.1-)
- rupture where an abnormal force is applied to normal tissue - see injury of tendon by body region
- arthropathic psoriasis (L40.5-)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- compartment syndrome (traumatic) (T79.A-)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Notes
General instructions on how these codes are used.
- Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name M66.0, its category, or a range that includes it.
Excludes1 1
These codes carry an Excludes1 note naming M66.0: they are not reported together with it, unless the two conditions are unrelated.
- M71.2 Synovial cyst of popliteal space [Baker]synovial cyst of popliteal space with rupture (M66.0)
Excludes2 2
These codes carry an Excludes2 note naming M66.0: its condition is not part of those codes, and both may be reported when the patient has both.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Knee Injuries and Disorders
Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt or diseased, you have knee problems. Knee problems can cause pain and difficulty walking.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert M66.0 to ICD-9-CMHistory
Code HistoryHistory
Questions About M66.0Overview
What is the ICD-10 code for rupture of popliteal cyst?
The ICD-10-CM code for rupture of popliteal cyst is M66.0 (sometimes written as M660). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is M66.0 (Spontaneous rupture of synovium and tendon) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report rupture of popliteal cyst on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does M66.0 group to?
When rupture of popliteal cyst is the principal diagnosis on an inpatient stay, it groups to MS-DRG 557, 558, with relative weights from 0.8873 to 1.4883 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of M66.0?
Under the General Equivalence Mappings, rupture of popliteal cyst converts to ICD-9-CM 727.51 (popliteal synovial cyst) and 727.59 (rupture of synovium NEC). The mapping is approximate, so confirm the match fits the documentation.
