ICD-10-PCS Code for Methadone Maintenance: Procedure Code Group Overview

The International Classification of Diseases, Tenth Revision, Procedure Coding System (ICD-10-PCS) code group HZ91 includes procedures performed to administer pharmacotherapy using methadone for treatment of addiction. These ICD-10-PCS codes are used for inpatient documentation when a patient receives methadone maintenance as part of substance abuse treatment. Accurate coding within the ICD-10-PCS HZ91 group is essential for proper inpatient reimbursement, as it captures the pharmacotherapy provided and supports clinical documentation accuracy.

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Methadone Maintenance Pharmacotherapy Procedure Overview

Procedures in this group involve pharmacotherapy using methadone as a replacement medication for treatment of opioid use disorder. These interventions are part of substance abuse treatment and do not target a specific anatomical body system. Accurate coding of these pharmacotherapy procedures ensures inpatient records reflect the treatment provided and supports appropriate case mix assignment and payment.

Code Attributes

Character	ICD-10-PCS Category	Code Group Details
H	Section	Substance Abuse Treatment
Z	Body System	None
9	Operation	Pharmacotherapy
1	Body Part	Methadone Maintenance

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ICD-10-PCS Code for Methadone Maintenance: Procedure Code Group Overview

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Methadone Maintenance Pharmacotherapy Procedure Overview

Code Attributes

Character	ICD-10-PCS Category	Code Group Details
H	Section	Substance Abuse Treatment
Z	Body System	None
9	Operation	Pharmacotherapy
1	Body Part	Methadone Maintenance

When to Use

Use a code from this group when methadone maintenance pharmacotherapy is provided as part of inpatient substance abuse treatment for opioid use disorder. Codes are applied when the inpatient record documents initiation, continuation, or supervised administration of methadone maintenance therapy.

ICD-10-PCS Codes

1 rows

ICD-10-PCS Code	Description
HZ91ZZZ	Pharmacotherapy for Substance Abuse Treatment, Methadone Maintenance

Typical Clinical Scenarios

A patient with a history of severe opioid use disorder is admitted for supervised initiation of methadone maintenance after failed outpatient attempts and recent withdrawal symptoms. Inpatient admission is required to begin dosing, monitor for oversedation and cardiac effects, and stabilize the patient on a safe maintenance dose. A pharmacotherapy procedure from this group documents the initiation and supervised administration of methadone during the hospital stay. Typical codes: HZ91ZZZ
An adult on established methadone maintenance presents to the emergency department with acute medical issues and requires hospitalization; during the stay the inpatient team administers the patient’s regular methadone dose to prevent withdrawal. The procedure documents continuation of methadone maintenance pharmacotherapy while treating the acute medical condition to ensure stability and prevent withdrawal complications. Typical codes: HZ91ZZZ
A patient stabilized on methadone maintenance experiences dosing issues related to tolerance and requires an inpatient supervised dose adjustment and monitoring for adverse effects. The admission is focused on modifying the maintenance regimen under observation to achieve therapeutic effect and document safe pharmacotherapy changes. Typical codes: HZ91ZZZ

ICD-10-PCS Code For Nicotine Replacement: Procedure Code Group Overview

HZ92-LEVO-ALPHA-ACETYL-METHADOL-PHARMACOTHERAPY

ICD-10-PCS Code For Levo Alpha Acetyl Methadol: Procedure Code Group Overview

HZ93-ANTABUSE-PHARMACOTHERAPY

ICD-10-PCS Code For Antabuse: Procedure Code Group Overview

HZ94-NALTREXONE-PHARMACOTHERAPY

ICD-10-PCS Code For Naltrexone: Procedure Code Group Overview

HZ95-NALOXONE-ALTERATION

ICD-10-PCS Code For Naloxone: Procedure Code Group Overview

HZ96-CLONIDINE-PHARMACOTHERAPY

ICD-10-PCS Code For Clonidine: Procedure Code Group Overview

HZ97-BUPROPION-PHARMACOTHERAPY

ICD-10-PCS Code For Bupropion: Procedure Code Group Overview

HZ98-PSYCHIATRIC-MEDICATION-PHARMACOTHERAPY

ICD-10-PCS Code For Psychiatric Medication: Procedure Code Group Overview

HZ99-OTHER-REPLACEMENT-MEDICATION-PHARMACOTHERAPY

ICD-10-PCS Code For Other Replacement Medication: Procedure Code Group Overview

Frequently Asked Questions

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

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When to Use

ICD-10-PCS Codes

1 rows

ICD-10-PCS Code	Description
HZ91ZZZ	Pharmacotherapy for Substance Abuse Treatment, Methadone Maintenance

Typical Clinical Scenarios

A patient with a history of severe opioid use disorder is admitted for supervised initiation of methadone maintenance after failed outpatient attempts and recent withdrawal symptoms. Inpatient admission is required to begin dosing, monitor for oversedation and cardiac effects, and stabilize the patient on a safe maintenance dose. A pharmacotherapy procedure from this group documents the initiation and supervised administration of methadone during the hospital stay. Typical codes: HZ91ZZZ
An adult on established methadone maintenance presents to the emergency department with acute medical issues and requires hospitalization; during the stay the inpatient team administers the patient’s regular methadone dose to prevent withdrawal. The procedure documents continuation of methadone maintenance pharmacotherapy while treating the acute medical condition to ensure stability and prevent withdrawal complications. Typical codes: HZ91ZZZ
A patient stabilized on methadone maintenance experiences dosing issues related to tolerance and requires an inpatient supervised dose adjustment and monitoring for adverse effects. The admission is focused on modifying the maintenance regimen under observation to achieve therapeutic effect and document safe pharmacotherapy changes. Typical codes: HZ91ZZZ

ICD-10-PCS Code For Nicotine Replacement: Procedure Code Group Overview

HZ92-LEVO-ALPHA-ACETYL-METHADOL-PHARMACOTHERAPY

ICD-10-PCS Code For Levo Alpha Acetyl Methadol: Procedure Code Group Overview

HZ93-ANTABUSE-PHARMACOTHERAPY

ICD-10-PCS Code For Antabuse: Procedure Code Group Overview

HZ94-NALTREXONE-PHARMACOTHERAPY

ICD-10-PCS Code For Naltrexone: Procedure Code Group Overview

HZ95-NALOXONE-ALTERATION

ICD-10-PCS Code For Naloxone: Procedure Code Group Overview

HZ96-CLONIDINE-PHARMACOTHERAPY

ICD-10-PCS Code For Clonidine: Procedure Code Group Overview

HZ97-BUPROPION-PHARMACOTHERAPY

ICD-10-PCS Code For Bupropion: Procedure Code Group Overview

HZ98-PSYCHIATRIC-MEDICATION-PHARMACOTHERAPY

ICD-10-PCS Code For Psychiatric Medication: Procedure Code Group Overview

HZ99-OTHER-REPLACEMENT-MEDICATION-PHARMACOTHERAPY

ICD-10-PCS Code For Other Replacement Medication: Procedure Code Group Overview

Frequently Asked Questions

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

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Trek Health powers OpenPayer with a leading commercial payer intelligence platform, seamlessly converting fragmented payer data into actionable insights for provider organizations.

OpenPayer

ICD-10-PCS Code for Methadone Maintenance: Procedure Code Group Overview

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Methadone Maintenance Pharmacotherapy Procedure Overview

Code Attributes

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ICD-10-PCS Code for Methadone Maintenance: Procedure Code Group Overview

Sign up for ICD-10-PCS Code for Methadone Maintenance: Procedure Code Group Overview policy alerts

Methadone Maintenance Pharmacotherapy Procedure Overview

Code Attributes

When to Use

ICD-10-PCS Codes

Typical Clinical Scenarios

Related Codes

References

When to Use

ICD-10-PCS Codes

Typical Clinical Scenarios

Related Codes

References

ICD-10-PCS Code for Methadone Maintenance: Procedure Code Group Overview

Sign up for ICD-10-PCS Code for Methadone Maintenance: Procedure Code Group Overview policy alerts

Methadone Maintenance Pharmacotherapy Procedure Overview

Code Attributes

ICD-10-PCS Code for Methadone Maintenance: Procedure Code Group Overview

Sign up for ICD-10-PCS Code for Methadone Maintenance: Procedure Code Group Overview policy alerts

Methadone Maintenance Pharmacotherapy Procedure Overview

Code Attributes

When to Use

ICD-10-PCS Codes

Typical Clinical Scenarios

Related Codes

What does the ICD-10-PCS code group HZ91 represent?

Which specific ICD-10-PCS code is included in this group?

What section, body system, and operation attributes are assigned to these codes?

How does accurate coding within HZ91 affect inpatient records and reimbursement?

Are there related DRGs listed for the HZ91 code group?

References

When to Use

ICD-10-PCS Codes

Typical Clinical Scenarios

Related Codes

What does the ICD-10-PCS code group HZ91 represent?

Which specific ICD-10-PCS code is included in this group?

What section, body system, and operation attributes are assigned to these codes?

How does accurate coding within HZ91 affect inpatient records and reimbursement?

Are there related DRGs listed for the HZ91 code group?

References