ICD-10-CM 2027 diagnosis code
M65.312Trigger thumb, left thumb
M65.312 is a valid, billable ICD-10-CM code for trigger thumb, left thumb. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
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 M65.312
M65.312 is the ICD-10-CM diagnosis code for Trigger thumb, left thumb. It belongs to category M65 (synovitis and tenosynovitis), 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 M65.31 (Trigger thumb), M65.312 is specifically for Trigger thumb, left thumb. Related codes cover right thumb (M65.311) and unspecified thumb (M65.319).
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 727.03 (Trigger finger (acquired)).
Notes that apply from higher levels
Instructions written at a parent level also apply to M65.312.
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 →- 727.03Trigger finger (acquired)approximate
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 M65.312
Is M65.312 billable?
- Yes. M65.312 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can M65.312 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict M65.312 as a principal diagnosis.
Is M65.312 a CC or MCC?
- No. M65.312 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does M65.312 group to?
- M65.312 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 M65.312?
- The CMS General Equivalence Mappings map M65.312 to ICD-9-CM 727.03.