ICD-10-CM 2027 diagnosis code
M66.271Spontaneous rupture of extensor tendons, right ankle and foot
M66.271 is a valid, billable ICD-10-CM code for spontaneous rupture of extensor tendons, right ankle and foot. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Spontaneous rupture of extensor tendons, right ank/ft
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About M66.271
M66.271 is the ICD-10-CM diagnosis code for spontaneous rupture of extensor tendons, right ankle and foot. It belongs to category M66 (spontaneous rupture of synovium and tendon), block M65-M67 (disorders of synovium and tendon) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within M66.27 (spontaneous rupture of extensor tendons, ankle and foot), M66.271 is specifically for spontaneous rupture of extensor tendons, right ankle and foot. Related codes cover left ankle and foot (M66.272) and unspecified ankle and foot (M66.279).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 557 (Tendonitis, Myositis and Bursitis with MCC, relative weight 1.489) and DRG 558 (Tendonitis, Myositis and Bursitis without MCC, relative weight 0.8875), in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 727.68 (nontraumatic rupture of other tendons of foot and ankle).
Notes that apply from higher levels
Instructions written at a parent level also apply to M66.271.
› From M66 Spontaneous rupture of synovium and tendon
- rupture that occurs when a normal force is applied to tissues that are inferred to have less than normal strength
- rotator cuff syndrome (M75.1-)
- rupture where an abnormal force is applied to normal tissue - see injury of tendon by body region
Broader instructions also apply from Chapter 13: Diseases of the musculoskeletal system and connective tissue.
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 08 · Diseases and Disorders of the Musculoskeletal System and Connective Tissue
ICD-9-CM equivalent
Converter →- 727.68Nontraumatic rupture of other tendons of foot and ankleapproximate
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about M66.271
Is M66.271 billable?
- Yes. M66.271 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can M66.271 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict M66.271 as a principal diagnosis.
Is M66.271 a CC or MCC?
- No. M66.271 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does M66.271 group to?
- M66.271 is used in the MS-DRG v44.0 logic for MS-DRG 557 (Tendonitis, Myositis and Bursitis with MCC) and MS-DRG 558 (Tendonitis, Myositis and Bursitis without MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for M66.271?
- The CMS General Equivalence Mappings map M66.271 to ICD-9-CM 727.68.