Understanding the CPT® Code System
Discover how CPT® codes shape ophthalmic care and how new procedures become recognized codes.
The Academy provides specialty-specific input to Current Procedural Terminology (CPT®), helping ensure codes accurately reflect the realities of ophthalmic practice.
CPT® is the uniform language used to describe medical, surgical, and diagnostic services across the U.S. health care system. Maintained by the American Medical Association (AMA), the CPT® code set provides physicians, payers, and patients with a consistent way to report the services delivered in clinical practice. For ophthalmologists, CPT® codes underpin everything from routine office visits and diagnostic imaging to cataract surgery, intravitreal injections, and emerging surgical techniques.
Purpose of CPT® Codes
CPT® was first developed in 1966 to standardize how physicians describe the services they provide. Today, it is the most widely accepted nomenclature for reporting medical procedures and services in the United States, and it is updated annually to keep pace with changes in clinical practice, technology, and the broader health care landscape.
The CPT® coding system is designed to:
- Provide a uniform language that accurately describes medical, surgical, and diagnostic services
- Support efficient and consistent communication between providers, patients, payers, and government agencies
- Enable accurate claims processing and reimbursement
- Facilitate data collection for medical education, research, and analysis of health care utilization
The CPT® Editorial Panel
The AMA convenes the CPT® Editorial Panel — an independent body responsible for maintaining and updating the CPT® code set. The Panel meets three times each year to review applications for new and revised codes. Anyone can register to attend these hybrid meetings in person or virtually.
The Editorial Panel is supported by the CPT® Advisory Committee — physicians nominated by the national medical specialty societies represented in the AMA House of Delegates. The American Academy of Ophthalmology actively participates in this committee, providing specialty-specific input on how proposed code changes will affect ophthalmic practice.
How a CPT® Code Is Created
The CPT® code change process is open to anyone, including individual physicians, specialty societies, manufacturers, and third-party payers. Applications follow a structured workflow designed to ensure that every code change is supported by clinical evidence and reflects current practice.
Category I and Category III Codes — Knowing the Difference
Category I codes are updated annually by the CPT® Editorial Panel, with changes taking effect January 1. Category III codes are updated twice a year, in January and July.
Category I Codes | Category III Codes |
Format Five-digit numeric codes (e.g., 66984 — cataract extraction with IOL). | Format Alphanumeric codes ending in “T” (e.g., 0671T). |
Purpose Report services and procedures that are widely performed across the U.S. and consistent with contemporary medical practice. | Purpose Track utilization of emerging technologies, services, and procedures. Enable data collection during early adoption. |
Requirements FDA clearance or approval for any device or drug used. Performed by many practitioners across multiple geographic locations. Supported by peer-reviewed clinical literature demonstrating efficacy. | Requirements Does not require widespread use or FDA approval at the time of code assignment. Application should include a clinical rationale and any available evidence. |
Lifespan Permanent designation; reviewed and refined over time. | Lifespan Archived five years after publication unless converted to Category I or extended by the Editorial Panel. |
Reimbursement Category I codes typically go through the RUC survey process. Payment for a Category I, Level I code is based on the number of relative value units (RVUs) that CMS has assigned to it. | Reimbursement Category III codes do not go through the RUC survey process. Payers can choose whether to reimburse a Category III code. If they don’t, the patient may be responsible for payment. If they do, the payer determines what the service is worth. Ophthalmologists may have to submit additional documentation and/or appeals to receive payment for a Category III service. |
Ophthalmology example Phacoemulsification with IOL, intravitreal injection, OCT of the retina, trabeculectomy. | Ophthalmology example Newer minimally invasive glaucoma surgery (MIGS) devices and novel retinal imaging modalities often begin here. |
Newer minimally invasive glaucoma surgery (MIGS) devices and novel retinal imaging modalities often begin here
A Category III code is not a permanent designation. As clinical evidence accumulates and a procedure becomes more widely adopted, an applicant may submit the code for conversion to Category I — a critical pathway for many of the innovations that reach ophthalmic practice.
The CPT® and RUC processes are inextricably linked. When a code is elevated from Category III to Category I, the CPT® Panel will refer it to the RUC for survey and valuation. Additionally, if significant changes are made to an existing Category I code, the CPT® Panel may refer that code to the RUC as well.
What This Means for Ophthalmologists
When a new technology enters ophthalmic practice — a novel glaucoma device, for example, or a new retinal imaging modality — it will typically first be assigned a Category III code so utilization can be tracked. It can be challenging to get payers to cover Category III services. Once the procedure becomes a standard part of care and meets Category I criteria, the CPT® Panel can promote it to a permanent five-digit code that subsequently goes through the RUC process. That valuation process is what gives a code the broader payer recognition and RVU framework that makes consistent reimbursement possible.
If you have questions about the CPT® process, contact healthpolicy@aao.org.