ICD-10-CM 2027
ICD-10 code for underdosing
From the official ICD-10-CM alphabetic index entry “Underdosing”. Page updated September 29, 2026.
About coding underdosing
The ICD-10-CM code for underdosing is Z91.14 (Patient's other noncompliance with medication regimen). The official index lists 4 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on Z91.14.
Within Z91.1, choose Z91.14 (other noncompliance with medication regimen) only when documentation doesn't support a more specific option: noncompliance with dietary regimen (Z91.11), intentional underdosing of medication regimen (Z91.12), unintentional underdosing of medication regimen (Z91.13), noncompliance with renal dialysis (Z91.15) and noncompliance with other medical treatment and regimen (Z91.19).
To report this condition, pick the subcode that matches the documentation: Z91.141 (due to financial hardship) and Z91.148 (for other reason).
Code first: , if applicable, adverse effect of underdosing (T36-T50).
More specific underdosing codes (official index)
- intentional NEC Z91.128 — Patient's intentional underdosing of medication regimen for other reason
- due to financial hardship of patient Z91.120 — Patient's intentional underdosing of medication regimen due to financial hardship
- unintentional NEC Z91.138 — Patient's unintentional underdosing of medication regimen for other reason
- due to patient's age related debility Z91.130 — Patient's unintentional underdosing of medication regimen due to age-related debility
Common questions about underdosing ICD-10 codes
What is the ICD-10 code for underdosing?
- Z91.14 — Patient's other noncompliance with medication regimen (a header code; report a more specific subcode). More specific codes apply when the documentation supports them: Z91.128, Z91.120, Z91.138, Z91.130.
What is the ICD-10 code for intentional nec underdosing?
- Z91.128 — Patient's intentional underdosing of medication regimen for other reason.
What is the ICD-10 code for unintentional nec underdosing?
- Z91.138 — Patient's unintentional underdosing of medication regimen for other reason.
Is Z91.14 billable?
- No. Z91.14 is a header code. Report one of its more specific subcodes instead.