ICD-10 Code for Underdosing
The ICD-10-CM code for underdosing is Z91.14 — Patient's other noncompliance with medication regimen. This is the code the Alphabetic Index gives for underdosing with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).
Z91.14 cannot be submitted on a claim. It is a header code, so a more specific code from the list below is required.
Which underdosing code should you use?
The Alphabetic Index lists 5 codes under Underdosing. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.
By type
Underdosing intentional NEC
| due to financial hardship of patient | Z91.120 | Patient's intentional underdosing of medication regimen due to financial hardship |
Underdosing unintentional NEC
| due to patient's age related debility | Z91.130 | Patient's unintentional underdosing of medication regimen due to age-related debility |
Codes under Z91.14
Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources