ICD-10 Code Z91.19: Patient’s Noncompliance With Other Medical Treatment and Regimen – Complete Coding & Billing Guide

What Does ICD-10 Code Z91.19 Mean?

ICD-10 code Z91.19 classifies a patient’s noncompliance with medical treatment or a prescribed regimen for reasons other than medication-related nonadherence or dietary noncompliance. It falls under Chapter 21: Factors Influencing Health Status and Contact with Health Services, within the Z91 category of personal risk factors not elsewhere classified.

As of FY 2024 (effective October 1, 2023), Z91.19 was restructured from a standalone billable code into a non-billable parent/header code. Coders must now select one of its child codes to submit a valid HIPAA-covered claim.

Key attributes of Z91.19:

• Billable status: Non-billable; not valid for direct HIPAA claim submission as of FY 2024
• POA reporting: Exempt from Present on Admission (POA) reporting
• Principal diagnosis: Unacceptable as a principal diagnosis; used as a secondary code
• Applicable to: Patient-reported or provider-observed nonadherence to prescribed therapies, procedures, follow-up regimens, or lifestyle recommendations
• Applicable synonym: “Patient’s nonadherence to medical treatment” is an official inclusion term

Why Is Z91.19 Non-Billable and What Codes Should You Use Instead?

Z91.19 became a non-billable header code in FY 2023, when CMS expanded the code set to require coders to specify the underlying reason for noncompliance. Submitting Z91.19 on a claim after October 1, 2023 will result in a rejection for lack of code specificity under ICD-10-CM Official Coding Guidelines, which require codes to be reported at their highest level of detail.

To select the correct billable child code, follow these steps:

1. Review the clinical documentation for any stated reason for the patient’s noncompliance.
2. Determine whether noncompliance involves a non-medication treatment — if it involves underdosing or medication, use the Z91.1x medication noncompliance or T36–T50 underdosing codes instead.
3. If the reason is financial hardship (e.g., cannot afford physical therapy, testing costs, specialist follow-up), select Z91.190.
4. If the reason is documented but falls outside financial hardship (e.g., cultural beliefs, transportation barriers, personal preference, fear of side effects), select Z91.198.
5. If the provider documents noncompliance but does not state a reason, select Z91.199.

What Are the Billable Child Codes Under Z91.19?

In practice, coders frequently default to Z91.199 when they should be querying the provider. If any hint of a reason appears in nursing notes, care coordinator documentation, or the discharge summary, Z91.190 or Z91.198 is the more defensible choice.

When Is It Appropriate to Use the Z91.19 Code Family?

These codes are used when a provider documents that a patient is not following — or has not followed — a prescribed non-medication medical treatment or regimen. They serve as secondary diagnoses explaining a circumstance that influences health status.

Appropriate use criteria:

1. The provider (physician, NP, PA, or qualified clinical professional) has explicitly documented noncompliance, nonadherence, or refusal of a prescribed treatment.
2. The noncompliance involves a non-medication regimen — examples include physical therapy, wound care, dietary monitoring, glucose testing, dialysis attendance, post-surgical restrictions, or scheduled follow-up.
3. The noncompliance is clinically relevant to the current encounter — it is affecting the patient’s condition or the treatment plan being documented.
4. A corresponding primary diagnosis code is present on the claim (these Z codes do not stand alone as principal diagnoses).
5. The type of noncompliance does not fall under dietary (Z91.11), medication (Z91.12x–Z91.13x), or caregiver noncompliance (Z91.A-).

How Does Z91.19 Differ From Z91.11 and Z91.A-?

The Excludes2 note at Z91.19 means a patient can carry both Z91.19x and Z91.A- simultaneously — for example, an elderly patient with dementia who is personally noncompliant AND whose caregiver is also failing to administer prescribed therapies.

What Documentation Is Required to Support Noncompliance Coding?

Accurate medical billing documentation for noncompliance codes depends entirely on provider-authored language. Coders cannot infer or assume noncompliance — it must be explicitly stated in the medical record.

What Must the Provider Document in Clinical Notes?

1. An explicit statement that the patient is noncompliant with, nonadherent to, or refusing a specific prescribed treatment or regimen.
2. The type of treatment or regimen involved (e.g., “patient has not attended physical therapy,” “patient stopped attending wound care visits”).
3. The reason for noncompliance, if known and obtainable — this determines whether Z91.190, Z91.198, or Z91.199 applies.
4. Clinical relevance: a note connecting the noncompliance to the patient’s current condition or care plan (e.g., “wound dehiscence likely due to patient’s failure to keep follow-up dressing appointments”).
5. Any counseling or patient education provided regarding the consequences of noncompliance.

What Is the Documentation Standard for Inpatient vs. Outpatient Settings?

Outpatient / Clinic:

• Noncompliance must appear in the provider’s assessment/plan section, not only in nursing intake notes
• Code only conditions that affect the current encounter’s management
• A care coordinator or social worker note documenting financial barriers can support Z91.190 when co-signed or referenced by the ordering provider

Inpatient:

• Noncompliance codes may be assigned for any condition that affects the patient’s care during the admission — even if not the primary reason for admission
• Query the attending physician if nursing notes or care management documentation references noncompliance but the physician’s notes are silent
• Z codes in the inpatient setting are exempt from POA reporting, so no POA indicator is required

How Does the Z91.19 Code Family Affect Medical Billing and Claims?

Noncompliance codes are secondary, circumstantial codes and do not independently drive reimbursement. Their primary billing value is supporting medical necessity, providing clinical context for otherwise unusual treatment patterns, and documenting quality care measures that may affect value-based payment contracts.

Key billing considerations:

• These codes cannot serve as the principal diagnosis on any claim type
• They are POA-exempt, meaning inpatient claims require no POA indicator
• Documenting the reason for noncompliance (Z91.190 vs. Z91.198 vs. Z91.199) can support social determinants of health (SDOH) reporting requirements under value-based care contracts
• Some payers use noncompliance documentation to deny repeat procedures — for example, a second colonoscopy denied because poor prep (noncompliance) is coded without adequate justification
• For HEDIS and quality measure reporting, these codes may flag patients as high-risk, supporting care management program enrollment

What CPT Codes Are Commonly Billed Alongside Noncompliance Codes?

Are There Prior Authorization or Coverage Restrictions?

• Z91.19x codes themselves do not trigger prior authorization requirements
• However, claims where a repeat or replacement service is linked to patient noncompliance (e.g., repeated wound care due to missed dressing changes) may face medical necessity scrutiny
• Commercial payers may reference noncompliance coding during post-payment audits to challenge the necessity of recurring services
• CMS does not publish a specific LCD for noncompliance codes; coverage determinations are procedure-driven, not diagnosis-driven

What Coding Errors Should You Avoid With Z91.19?

The most common errors with this code family involve either using the non-billable parent code or under-specifying the reason for noncompliance — both of which create revenue cycle compliance risk.

1. Submitting Z91.19 directly on a claim — this code is not valid for HIPAA transactions; always use Z91.190, Z91.198, or Z91.199.
2. Defaulting to Z91.199 (unspecified) when a reason is documented — auditors consider this under-coding if the reason for noncompliance appears anywhere in the record.
3. Using Z91.19x for medication noncompliance — if the patient is taking less medication than prescribed, the Z91.12x–Z91.13x codes (and T36–T50 underdosing codes) apply; Z91.19x is for non-medication regimens.
4. Using Z91.19x when the caregiver is the noncompliant party — in pediatric, home health, or memory care settings, always evaluate whether Z91.A- is the more accurate family.
5. Assigning noncompliance codes without explicit provider documentation — coders cannot self-assign noncompliance; it must originate from a qualified clinician’s documentation.
6. Listing a Z91.19x code as the principal diagnosis — these codes are never acceptable as the first-listed diagnosis.

What Do Auditors Look for When Reviewing Noncompliance Claims?

• Provider documentation that explicitly uses the word “noncompliant,” “nonadherent,” or “refusing” — not just implied behavior
• Consistency between the selected child code and the documented reason (e.g., Z91.190 requires financial hardship language in the notes)
• Whether noncompliance documentation appears in the physician’s note versus only in nursing or ancillary staff notes
• Whether the noncompliance code is clinically relevant to the services billed on the same claim
• Patterns of repeated Z91.199 (unspecified) usage that suggest a documentation gap rather than a genuine absence of known reason

How Does Z91.19 Relate to Other ICD-10 Codes?

Understanding the Z91.19 family within the broader ICD-10-CM Official Coding Guidelines code hierarchy is essential for correct sequencing and avoiding inadvertent Excludes1 violations.

What Is the Correct Sequencing When a Noncompliance Code Appears With Other Diagnoses?

1. Sequence the primary condition being treated (the reason for the encounter) first — for example, uncontrolled type 2 diabetes (E11.65) as principal diagnosis.
2. Sequence the noncompliance code (e.g., Z91.198) as a secondary/additional diagnosis that explains a contributing circumstance.
3. If a SDOH code (Z55–Z65) explains the reason for noncompliance — such as housing instability preventing follow-up care — it may be coded additionally to support population health and value-based care documentation.
4. If a procedure was not performed due to patient refusal, pair Z53.21 (procedure not carried out due to patient refusal) alongside the noncompliance code where supported by documentation.
5. Never sequence a Z91.19x code before the primary diagnosis it contextualizes.

Real-World Coding Scenario — How Noncompliance Codes Are Applied in Practice

Scenario: A 58-year-old male with a history of peripheral artery disease presents to his vascular surgeon’s office for a follow-up visit. The provider documents that the patient has not been performing prescribed wound care for a venous ulcer on his left lower leg, resulting in worsening of the wound. The patient states he cannot afford the wound care supplies. The provider counsels the patient extensively and documents the conversation.

Correct Code Application

• L97.329 — Non-pressure chronic ulcer of left calf with unspecified severity (primary diagnosis; reason for encounter)
• Z91.190 — Patient’s noncompliance with other medical treatment due to financial hardship (the patient explicitly cited cost as the barrier; wound care is a non-medication regimen)
• 99214 — Office visit, established patient, moderate medical decision-making (E&M for the encounter)

Why it works: Financial hardship is documented by the provider. The noncompliance directly explains the wound’s deterioration and is clinically relevant to the visit. Z91.190 is the correct billable child code.

Common Mistake in This Scenario

• Incorrect code selected: Z91.19 (the non-billable parent code submitted directly on the claim)
• Why it fails: Z91.19 has been non-billable since FY 2024; the claim will reject at the clearinghouse for insufficient code specificity
• Second common mistake: Z91.199 (unspecified reason) when the documentation clearly identifies financial hardship — this constitutes under-coding and could misrepresent the patient’s SDOH profile in population health data

Frequently Asked Questions About ICD-10 Code Z91.19

Is ICD-10 Code Z91.19 Still Valid in 2026?

Z91.19 remains a valid ICD-10-CM classification code in FY 2026, but it is not valid for direct claim submission. It functions as a non-billable header code that organizes its three billable child codes — Z91.190, Z91.198, and Z91.199 — which are the codes appropriate for HIPAA-covered transactions.

What Is the Difference Between Z91.19 and Z91.199?

Z91.19 is the parent, non-billable category code; it cannot be submitted on a claim. Z91.199 is a distinct billable child code used when noncompliance with a non-medication medical treatment is documented but no reason for that noncompliance is stated in the record. Coders should use Z91.199 only after confirming the record genuinely contains no documented reason — not as a default shortcut.

Can Z91.19x Codes Be Used as a Primary Diagnosis?

No. Codes in the Z91.19x family are unacceptable as a principal or first-listed diagnosis under ICD-10-CM Official Coding Guidelines. They describe circumstances that influence health status rather than active illnesses or injuries, and must always accompany a primary diagnosis code that reflects the condition being treated.

When Should I Use Z91.190 Instead of Z91.198?

Use Z91.190 when the provider’s documentation specifically identifies financial hardship as the reason the patient has not followed the prescribed treatment — including references to cost, lack of insurance coverage, inability to pay for supplies, or socioeconomic barriers to accessing care. Use Z91.198 when a different reason is documented, such as cultural beliefs, fear, transportation difficulties, or patient preference.

How Do I Code Noncompliance When It’s the Caregiver Who Is Nonadherent, Not the Patient?

When the caregiver — not the patient — is failing to follow the prescribed treatment regimen, use the Z91.A- code family, not Z91.19x. This distinction matters most in pediatric encounters, memory care, home health settings, and cases involving dependent adults. The Excludes2 note at Z91.19 confirms that both Z91.19x and Z91.A- can be reported simultaneously if both the patient and caregiver are each independently noncompliant.

What Happens If I Submit Z91.19 (the Parent Code) on a Claim?

A claim submitted with Z91.19 as a diagnosis code will be rejected during HIPAA transaction validation because the code lacks the required specificity for electronic billing. The clearinghouse or payer will flag the code as invalid, resulting in a denial or rejection that must be corrected and resubmitted with the appropriate child code (Z91.190, Z91.198, or Z91.199).

Does Coding Noncompliance Hurt the Patient or Affect Their Coverage?

Noncompliance codes document clinical circumstances — they do not, by themselves, disqualify a patient from coverage or services. However, payers may reference noncompliance documentation during utilization review to evaluate the medical necessity of repeated procedures. Accurate coding with supporting documentation actually protects providers by demonstrating clinical rationale, whereas absent or vague documentation creates both audit exposure and care coordination gaps that can affect revenue cycle compliance.

Key Takeaways

Everything a coder or biller needs to remember about the Z91.19 code family:

• Z91.19 is non-billable as of FY 2024; always use Z91.190, Z91.198, or Z91.199 on claims
• The choice between child codes depends entirely on documented reason for noncompliance — review the full record before defaulting to “unspecified”
• These codes apply to non-medication, non-dietary treatment noncompliance; separate code families exist for medications (Z91.12x/Z91.13x) and diet (Z91.11)
• Z91.A- is the correct family when the caregiver — not the patient — is nonadherent; both code sets can coexist on the same claim under the Excludes2 rule
• Noncompliance codes are always secondary diagnoses and are never acceptable as the principal or first-listed diagnosis
• Provider documentation must explicitly state noncompliance; coders cannot self-assign it from implied behavior
• Accurate noncompliance coding supports SDOH documentation, value-based care reporting, and medical necessity defense during post-payment audits

For further guidance, refer to the CMS ICD-10-CM Official Guidelines for Coding and Reporting and the AHA Coding Clinic for any published guidance on noncompliance code application. Additional context on Z code sequencing is available in the WHO ICD reference classification.