ICDcodes.org
FY2027

M66.18 — Rupture of synovium, other site

Billable

Is M66.18 billable?

Yes — M66.18 is billable for FY2027. M66.18 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. M66.18 may be submitted for encounters from October 1, 2026 through September 30, 2027.

M66.18 at a glance

CodeM66.18
DescriptionRupture of synovium, other site
BillableYes
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027

Which MS-DRGs does M66.18 group to?

M66.18 sits in MDC 08 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

  • 557Tendonitis, Myositis and Bursitis with MCCmedical
  • 558Tendonitis, Myositis and Bursitis without MCCmedical

How is M66.18 listed in the Alphabetic Index?

These are the routes through the Alphabetic Index that lead to M66.18. They show the wording a clinician may have documented, which often differs from the Tabular description.

  • Rupture, ruptured › synovium › specified site NEC

Excludes2 — not included here — inherited from Chapter 13

The conditions below are not part of M66.18, but a patient may have both at the same time. When documentation supports it, M66.18 and the excluded code may both be reported.

  • 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)

Excludes2 — not included here — inherited from M66

The conditions below are not part of M66.18, but a patient may have both at the same time. When documentation supports it, M66.18 and the excluded code may both be reported.

  • 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 — inherited from M66.1

The conditions below are not part of M66.18, but a patient may have both at the same time. When documentation supports it, M66.18 and the excluded code may both be reported.

  • rupture of popliteal cyst (M66.0)

How long has M66.18 existed?

M66.18 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.

Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.

What other codes are in the M66.1 family? (7)