Skip to main content
Headway

Billing and coding

The differences between CPT codes and HCPCS codes — and why they matter

Confused about CPT vs HCPCS codes? Learn the key differences, structure, and when to use each for accurate billing and insurance claims.

May 2, 2025

By Dr. Anum Ali, LPC

9 min read

By Dr. Anum Ali, LPC

Understanding the difference between CPT and HCPCS codes is crucial for healthcare providers who want to ensure accurate billing and avoid insurance claim issues. Both coding systems play a significant role in how healthcare services are documented and reimbursed. However, many healthcare professionals, particularly those new to the field, can find it confusing to navigate these codes. 

This article will clarify the distinctions between CPT and HCPCS codes, their structures, when to use them, and why they matter for accurate billing and coding practices. To dive deeper into CPT codes and general documentation, consult our comprehensive guide.

What are CPT codes?

Current Procedural Terminology (CPT) codes were developed in the 1960s by the American Medical Association (AMA). They are a set of codes used to describe medical, surgical, and diagnostic services. Maintained by the AMA, these codes are widely used by healthcare providers in both private and public healthcare systems, including Medicaid and Medicare. Behavioral health providers rely on CPT codes to bill for services such as therapy sessions, psychological testing, and psychiatric evaluations.

CPT codes play an essential role in the billing process, ensuring that healthcare services are accurately documented and reimbursed. They also help to streamline communication between healthcare providers, insurers, and patients. Learn more about specific CPT codes for behavioral health.

Code structure

  • Category I: Category I CPT codes are the most common and represent the standard procedures or services provided by healthcare providers. These codes are used for everything from weekly therapy sessions to comprehensive psychological evaluations.
  • Category II: Category II codes are used for performance measurement and are intended to help track the quality of care provided. These codes are not typically used for reimbursement purposes but can be helpful for improving healthcare delivery.
  • Category III: Category III codes are temporary codes used to track emerging technologies, procedures, and services. These codes are often used for experimental or new services not yet widely accepted or approved for general use.

What are HCPCS codes?

Healthcare Common Procedure Coding System (HCPCS) codes are used to describe medical services and equipment not covered under the CPT system. These codes are essential for Medicare, Medicaid, and other insurance claims. HCPCS codes are used to capture a broader range of services, including durable medical equipment, prosthetics, ambulance services, and certain medications and supplies that are not listed under CPT codes.

Code structure

  • Level I: Level I HCPCS codes are identical to CPT codes and are used to describe medical procedures and services. These codes are the same as the Category I CPT codes and are managed by the AMA.
  • Level II: Level II HCPCS codes are used for non-physician services, including medical equipment, medications, and other supplies not covered by the CPT system. These codes are managed by the Centers for Medicare and Medicaid Services (CMS) and are widely used for billing services not covered under the standard CPT codes.

Practice in-network with confidence

Simplify insurance and save time on your entire workflow — from compliance and billing to credentialing and admin.

Talk to a practice consultant

Key differences between CPT & HCPCS

Definition

CPT codes: Used to describe medical, surgical, and diagnostic procedures

HCPCS codes: Used for non-physician services, equipment, and other healthcare services not covered under CPT

Ownership

CPT codes: Managed by the American Medical Association (AMA)

HCPCS codes: Managed by the Centers for Medicare & Medicaid Services (CMS)

Protection

CPT codes: Copyright by the AMA

HCPCS codes: Public domain, free for use

Purpose

CPT codes: To document and standardize medical procedures and services

HCPCS codes: To capture a wider range of healthcare services not included under CPT

Structure

CPT codes: Category I, II, III codes

HCPCS codes: Level I (same as CPT), Level II codes

Common code examples

Now that we understand the differences between CPT and HCPCS codes, let's explore some common examples. Here are three common CPT codes, as defined by the AMA, and four HCPCS codes. (For more detailed examples, check out the top 10 most common CPT codes.)

Common CPT codes

90834: Psychotherapy, 45 minutes with patient

Psychotherapy is the treatment of mental illness and behavioral disturbances in which the physician or other qualified health care professional, through definitive therapeutic communication, attempts to alleviate the emotional disturbances, reverse or change maladaptive patterns of behavior, and encourage personality growth and development.

The psychotherapy service codes include ongoing assessment and adjustment of psychotherapeutic interventions, and may include involvement of informants in the treatment process. These codes describe psychotherapy for the individual patient, although times are for face-to-face services with patient and may include informant(s). The patient must be present for all or a majority of the service.

90847: Family psychotherapy (conjoint psychotherapy) (with patient present), 50 minutes

Psychotherapy is the treatment of mental illness and behavioral disturbances in which the physician or other qualified health care professional, through definitive therapeutic communication, attempts to alleviate the emotional disturbances, reverse or change maladaptive patterns of behavior, and encourage personality growth and development.

99213: Existing patient office visit, minimum 20 minutes

Office or other outpatient visit for the evaluation and management of an established patient, which requires a medically appropriate history and/or examination and low level of medical decision making. When using total time on the date of the encounter for code selection, 20 minutes must be met or exceeded.

99214: Existing patient office visit, minimum 30 minutes

Office or other outpatient visit for the evaluation and management of an established patient, which requires a medically appropriate history and/or examination and moderate level of medical decision making. When using total time on the date of the encounter for code selection, 30 minutes must be met or exceeded.

99203: New patient office visit, minimum 30 minutes

Office or other outpatient visit for the evaluation and management of a new patient, which requires a medically appropriate history and/or examination and low level of medical decision making. When using total time on the date of the encounter for code selection, 30 minutes must be met or exceeded.

Common HCPCS codes

  • A4590: General medical supplies. While not commonly used by therapists, this code may appear in facility billing when supplies are involved.
  • H0031: Mental health assessment by non-physician. Often used for initial evaluations by licensed clinical social workers (LCSWs), licensed professional counselors (LPCs), or other non-MD behavioral health providers.
  • H0032: Mental health service plan development by non-physician. Used when a therapist is creating or updating a treatment plan, often in Medicaid programs.
  • H0004: Behavioral health counseling and therapy, per 15 minutes. A general code widely used by mental health therapists for individual therapy sessions, especially in state Medicaid billing systems.

When to use CPT vs. HCPCS codes

Both CPT and HCPCS codes are crucial in medical billing, but they are used in different contexts. CPT codes are primarily used for procedures and services provided by healthcare professionals like therapists, particularly in office visits and hospital settings. These are the codes used when reporting medical services for reimbursement under private insurers and Medicare.

HCPCS codes, on the other hand, are typically used for services and items that fall outside of the standard CPT system, such as medical equipment, ambulance services, and medications. These codes are particularly important for providers working with Medicare and Medicaid, as they capture services and equipment often not included in CPT.


To summarize:

  • Use CPT codes when documenting procedures like office visits, surgeries, and diagnostic tests.
  • Use HCPCS codes for medical supplies, durable medical equipment, and non-physician services.

Why understanding codes is important

Understanding CPT and HCPCS codes is essential for healthcare providers to ensure accuracy in their billing and coding processes.

Ensures accurate billing

Accurate coding ensures that providers are paid correctly for their services. Without the right codes, claims can be delayed or denied, leading to financial losses.

Improves communication between providers and patients

Proper coding facilitates communication between healthcare providers, insurance companies, and patients. It ensures that everyone is on the same page regarding the services provided.

Avoids claim denials and delays

Using the wrong code or failing to use a code can result in claim denials or delays. These delays can cause financial strain on your practice and impact the quality of care your patients receive. Headway’s documentation services can help streamline this process, reducing errors and saving valuable time.

Complies with legal and insurance standards

Adhering to the correct coding standards ensures compliance with insurance regulations and avoids potential legal issues for healthcare providers.

Tracking and reporting patient care

Proper use of CPT and HCPCS codes allows providers to track patient care and outcomes more effectively, improving overall healthcare delivery.


FAQs

1. How do I find the correct CPT or HCPCS code for my service?

You can find the appropriate codes through coding manuals, online coding tools, or by consulting with coding experts. For more help, consult the American Academy of Professional Coders (AAPC).

2. Do private insurers require HCPCS codes?

Private insurers may require HCPCS codes for specific services, especially for durable medical equipment and non-physician services. It’s important to check the specific requirements for each insurer.

3. How often are CPT and HCPCS codes updated?

Both CPT and HCPCS codes are updated annually to reflect changes in medical practices, procedures, and technologies. Staying updated on these changes is crucial for accurate billing.

4. What happens if I use the wrong code?

Using the wrong code can result in claim denials, delays in reimbursement, or even potential legal issues. It’s essential to double-check codes to ensure they match the services provided.


Practice in-network with confidence

Navigating CPT and HCPCS codes can be complex, but with the right resources, it doesn’t have to be overwhelming. Headway’s billing and coding policies are designed to help providers ensure accuracy in their claims and avoid common mistakes.

Talk to a practice consultant

This content is for general informational and educational purposes only and does not constitute clinical, legal, financial, or professional advice. All decisions should be made at the discretion of the individual or organization, in consultation with qualified clinical, legal, or other appropriate professionals.

© 2026 Therapymatch, Inc. dba Headway. All rights reserved. No part of this publication may be reproduced without permission.

Billing and coding

How to bill insurance for therapy

Headway strives to simplify billing insurance so you can focus on providing care. Read our comprehensive guide to mental health billing.