Your patient is taking less medication than prescribed, but the visit note only says “patient is noncompliant.” Your coder now has to determine what the documentation supports before assigning the ICD-10 code.
For your agency, that missing information can mean more coding queries, claim rework and compliance risk.
Key Takeaways
Identify who was noncompliant, what happened with the medication regimen and why it happened before coding.
Distinguish underdosing, poisoning, adverse effects and noncompliance before assigning a code.
Assign a designated owner and a response process for unresolved coder queries before the claim is submitted.
The ICD-10 Codes for Noncompliance With Medication, ICD-10-CM Diagnosis and Medical Treatment
According to the CMS FY2027 Official Guidelines for Coding and Reporting, medication-related coding depends on what happened with the medication and what the documentation supports.
The main distinctions are:
- Underdosing: The patient takes less medication than prescribed or stops a prescribed medication on their own. Assign the applicable T36-T50 code with a fifth or sixth character of 6.
- Poisoning: The medication is used improperly, such as an overdose, wrong medication taken in error or wrong route of administration. The T36-T50 code uses a fifth or sixth character that identifies the intent.
- Adverse effect: The medication was correctly prescribed and properly administered, but caused a harmful reaction. The T36-T50 code uses a fifth or sixth character of 5.
- Noncompliance: A Z91 category may provide additional information about the patient’s or caregiver’s noncompliance. For underdosing, CMS identifies Z91.12-, Z91.13-, Z91.14- and Z91.A4- as codes that may be assigned with the applicable underdosing code to indicate intent, if known.
Code Reference Table
Code Family/Category | Documentation Supports | What the Coder Needs to Establish | What a Documentation Gap Can Cause |
|---|---|---|---|
Z91.12- | Patient intentional underdosing on a medication regimen | Patient, underdosing, intent and applicable reason | Query or unsupported code selection |
Z91.13- | Patient unintentional underdosing on a medication regimen | Patient, underdosing and applicable reason | Query or unsupported code selection |
Z91.14- | Patient’s other noncompliance with medication regimen | Patient, noncompliance and applicable reason | Query or incorrect category |
Z91.A4- and applicable subdivision | Caregiver’s other noncompliance with the patient’s medication regimen | Caregiver, medication noncompliance and applicable reason | Query or incorrect code selection |
T36-T50 with character 6 | Underdosing of a drug, medicament or biological substance | Drug involved and underdosing | Incomplete code selection |
T36-T50, applicable poisoning character | Poisoning involving a drug, medicament or biological substance | Drug involved and intent | Incorrect poisoning classification |
T36-T50 with character 5 | Adverse effect of a drug, medicament or biological substance | Drug involved and adverse effect | Incorrect adverse-effect classification |
Patient and Caregiver Noncompliance Codes
The ICD-10-CM diagnosis code should reflect what the record supports. Healthcare professionals and coders need to distinguish medication noncompliance from poisoning, adverse effects and underdosing before selecting the applicable code.
The T36-T50 categories cover poisoning, adverse effects and underdosing involving drugs, medicaments and biological substances. The required characters identify the event and encounter type. For underdosing, CMS specifies a fifth or sixth character of 6.
For a patient, document:
- The medication and prescribed regimen.
- What the patient took or didn’t take.
- Whether the patient took less medication than prescribed or stopped taking it.
- Whether the action was intentional, if documented.
- Any documented reason, such as financial hardship or another relevant circumstance.
- Any applicable risk factors or other factors not elsewhere classified (NEC), when supported by the documentation.
CMS also instructs coders not to assign a drug code directly from the Table of Drugs and Chemicals. The coder must verify the code in the Tabular List and follow the applicable coding instructions. The record needs to show what was prescribed and what the patient or caregiver actually did.
What the Home Health Record Must Show for an ICD-10-CM Diagnosis
The ICD-10-CM code should be based on what the home health record supports. A clear note gives the coder enough information to identify the medication issue without creating undocumented facts.
Use Who → What → Why as a practical documentation check:
Who: Identify whether the patient or caregiver was responsible for the medication issue.
- Name the person responsible for managing the medication.
- Don’t make the coder infer responsibility from the surrounding patient care record.
- If a caregiver manages the medication regimen, document that role.
What: Describe what actually happened with the medication or medical treatment.
- Name the medication.
- Document the prescribed instructions and what was actually taken or not taken.
- State whether the patient took less medication, stopped the medication, missed doses or did something else.
- Document the provider’s diagnosis or assessment when applicable.
For underdosing, CMS states that documentation showing the patient took less medication than prescribed or discontinued the prescribed medication is sufficient for code assignment. A change in the patient’s condition isn’t required.
Why: Record the stated reason when one is documented.
- Document financial hardship, age-related debility or another documented reason when applicable.
- If the record supports another reason, state what that was.
- Do not use personal risk factors, personal history or other information provided elsewhere in the chart to create a reason that was not documented.
- If no reason or intent is documented, your coders shouldn’t infer reasons or intent absent from the documentation.
Who → What → Why is a practical documentation review method, not an ICD-10-CM rule that every code requires all three elements. The coder must apply the current code set, Tabular List instructions and official guidelines to the documentation available. CMS states that code assignment is based on the provider’s diagnostic statement and that conflicting documentation should be clarified with a provider query.
Documentation Examples Table
Weak Documentation | What’s Missing | What to Do |
|---|---|---|
“Patient is noncompliant with medications.” | Which medication and what actually happened | Name the medication and describe what the patient or caregiver did or didn’t do. |
“Patient missed medication.” | What medication was missed and what was actually taken | Document the medication, prescribed instructions, actual administration, responsible party and stated reason. |
“Patient taking less medication.” | Actual dose, prescribed dose and reason | Document both doses, the patient’s explanation and the relevant circumstance. |
“Caregiver not compliant.” | Caregiver’s role and medication management action | Identify what the caregiver was responsible for and what occurred. |
“No reason given.” | Whether a reason or intent was assessed | Document the reason or intent when known and relevant to code selection. |
Remember:
A medication issue can exist alongside another diagnosis or condition being treated. A Z91 code doesn’t automatically replace the condition that requires medical treatment. The coder should report the conditions and circumstances supported by the record and apply the applicable coding instructions.
How Noncompliance With Medication ICD-10 Documentation Moves From the Visit to the Claim
The medication issue starts in patient care, moves through documentation and coding and is checked before the diagnosis is reported on the claim. Each handoff needs a clear owner, so missing or conflicting information is addressed before submission.
Home Health Medication Noncompliance Workflow
Workflow Stage | Primary Owner/s | Common Failure | Verification Point |
|---|---|---|---|
Visit assessment | Clinicians | Patient’s noncompliance is documented without identifying what happened or who was responsible | Note the medication, actual behavior, responsible party and documented explanation |
Medication reconciliation/medication regimen review | Clinicians | Medication list and visit documentation do not agree | Compare the active medication record with the visit findings |
Coding review | Medical coders | Coder can’t determine the applicable ICD-10-CM diagnosis from the record | Confirm the documented type of noncompliance and the responsible party |
Coder query | Coders + clinicians | Query remains unanswered or incomplete | Assign an owner and define a response timeframe |
Pre-claim QA | QA/coding leads | Diagnosis or code is reviewed after submission | Confirm diagnosis selection and supporting documentation before billing |
Claim submission | Billers | Confirm the reported diagnosis is supported by the record |
The OASIS, plan of care, medication record and visit notes should support the patient’s overall clinical picture. They shouldn’t replace documentation of what actually happened with the medication regimen.
If the record doesn’t establish the applicable diagnosis or noncompliance with medical treatment, the coder should query the provider rather than infer the missing information. CMS requires complete documentation and review of the entire record for accurate code assignment.
Before the claim is reported, confirm:
- The record supports the documented medication issue and the medical treatment and regimen involved in patient care.
- When a reason is documented, confirm that financial hardship, age-related debility or other reason matches the applicable ICD-10-CM category.
- Healthcare professionals and coders resolve conflicting documentation before the final code is reported.
Closing the Staffing Capacity Gap in Home Health Services for ICD-10-CM Documentation
External support can take on repeatable documentation work such as tracking queries, gathering records and checking charts for missing information. This gives licensed staff more time for patient care while they retain responsibility for patient assessment, clinical judgment, diagnosis decisions and the responses needed to finalize the ICD-10-CM diagnosis.
Where External Support Fits
Function | External Support Can Handle | Keep Internal |
|---|---|---|
Query tracking | Log queries, monitor status, send defined follow-ups and report unresolved items | Clinical response and final documentation decision |
Chart preparation | Assemble the relevant visit notes, medication records and supporting documentation for review | Clinical interpretation |
Pre-claim documentation review | Check whether required documentation elements are present and flag gaps | Diagnosis selection and clinical judgment |
Defect logging | Record recurring documentation defects and prepare trend reports | Decide on corrective clinical or operational action |
Record retrieval | Locate defined records needed for coding or QA review | Determine what documentation supports the final code |
Before You Hand Off Any Function
- Define the task. Set the expected output, volume and standard before assigning the work.
- Set the boundaries. Define what support can handle, when to contact your team and what stays internal.
- Document the workflow. List the steps, required access and who owns the final decision.
- Assign accountability. Name the internal person responsible for review and exceptions while allowing support to work with independence within defined limits.
- Measure the result. Track turnaround time, completion rates, errors and internal time saved.
Frequently Asked Questions
There is no single ICD-10 code for every medication noncompliance situation. Current ICD-10-CM codes include Z91.120 and Z91.128 for intentional underdosing, Z91.130 and Z91.138 for unintentional underdosing and Z91.141 and Z91.148 for other noncompliance with a medication regimen. The correct code depends on what happened and what the documentation supports.
No. Z91.14 is the category for the patient’s other noncompliance with a medication regimen. The current billable codes are Z91.141, for noncompliance due to financial hardship and Z91.148, for noncompliance for another reason. The ICD-10-CM diagnosis should be reported to the highest level of specificity supported by the documentation.
Underdosing is a specific type of medication noncompliance. It occurs when a patient takes less medication than prescribed or stops a prescribed medication on their own. ICD-10-CM reports the drug involved with a T36-T50 underdosing code. Z91 codes can also be used with underdosing or other medication noncompliance when supported by the documentation and applicable coding instructions.
It can, depending on the specific code and the services provided. CMS states that an underdosing T36-T50 code can’t be the principal or first-listed diagnosis. A Z91 code for noncompliance with medical treatment is different. If a Z91 code is considered for first-listed reporting, the coder must apply the home health sequencing rules and confirm that it reflects the condition chiefly responsible for the health services provided.
The code depends on what the caregiver did and whether the documentation supports intentional or unintentional underdosing or another type of noncompliance. Z91.A20 applies to intentional underdosing due to financial hardship, Z91.A28 to intentional underdosing for another reason and Z91.A3 to unintentional underdosing. Z91.A41 and Z91.A48 apply to other caregiver noncompliance with the patient’s medication regimen.
