ICD-10-CM 2027
ICD-10 code for Lynch syndrome
From the official ICD-10-CM alphabetic index entry “Syndrome › Lynch (due to EPCAM) (due to MLH1) (due to MSH2) (due to MSH6) (due to PMS2)”. Page updated September 29, 2026.
About coding Lynch syndrome
The ICD-10-CM code for Lynch syndrome is QA1.71 (Lynch syndrome).
Within QA1.7 (inherited neoplasm predisposition syndromes involving multiple systems, not elsewhere classified), QA1.71 is specifically for Lynch syndrome. Related codes cover other inherited neoplasm predisposition syndrome of multiple systems (QA1.79).
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 951 (Other Factors Influencing Health Status, relative weight 0.5577), in MDC 23 (Factors Influencing Health Status and Other Contacts with Health Services), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about Lynch syndrome ICD-10 codes
What is the ICD-10 code for Lynch syndrome?
- QA1.71 — Lynch syndrome.
Is QA1.71 billable?
- Yes. QA1.71 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can QA1.71 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict QA1.71 as a principal diagnosis.
Is QA1.71 a CC or MCC?
- No. QA1.71 is neither a CC nor an MCC under MS-DRG v44.0.