The 99423 CPT code covers an online digital E/M service for an established patient. It applies when a physician or qualified healthcare professional spends 21 minutes or more on the service within a week.
E/M services make up approximately 40% of all Medicare payment under the Physician Fee Schedule
This service supports patient care without requiring a traditional office visit. Providers can review the patient’s concern, assess the condition, and manage care through online communication. Proper time tracking and documentation remain essential for accurate billing.
What Is the 99423 CPT Code?
The 99423 CPT code represents the highest time tier for online digital E/M services. It applies to established patients who initiate an online digital service.
The provider must perform medically necessary evaluation and management work. The total professional time must reach at least 21 minutes during the seven-day period.
This service differs from a scheduled video visit. Communication may occur through a patient portal or another qualifying digital platform.
CPT 99423 Quick Facts
| Billing Detail | Requirement |
| Patient status | Established patient |
| Service type | Online digital E/M |
| Minimum time | 21 minutes |
| Time period | Up to seven days |
| Service initiation | Patient initiated |
| Provider | Physician or qualified healthcare professional |
| Documentation | Medical record required |
Providers should document the clinical work supporting the reported service. The record should also support the medical necessity of that work.
How Does CPT 99423 Work?
The patient first sends a qualifying online request. The provider then reviews the concern and performs the necessary clinical work.
The provider may review records, assess symptoms, develop a treatment plan, or order services. Relevant professional work accumulates throughout the seven-day period. Once the total time reaches 21 minutes, the highest applicable tier may be reported.
One Simple Example
A patient sends a portal message about worsening symptoms. The provider reviews records and responds with a treatment plan. Additional related work brings total time above 21 minutes. The provider documents the work and reports the appropriate online digital E/M codes
99423 vs 99422
Understanding 99423 vs 99422 helps providers select the correct time tier.
| CPT Code | Cumulative Time |
| 99421 | 5–10 minutes |
| 99422 | 11–20 minutes |
| 99423 | 21 minutes or more |
The main difference is cumulative professional time. Providers should not select 99423 simply because communication involves several messages. The documented professional work must support the reported time. Lacking evidences can lead to claim denials and revenue loss.
99423 as the Online Digital EVM Highest Tier
The online digital EVM highest tier applies when cumulative professional time reaches 21 minutes or more. This time is calculated across the applicable seven-day service period. Providers should track qualifying work carefully rather than estimating time after the service ends. The online digital EVM highest tier should reflect the actual documented clinical work performed.
What Counts Toward CPT 99423 Time?
Qualifying professional work may include:
- Reviewing the patient’s clinical information
- Evaluating the reported problem
- Reviewing relevant medical records
- Developing a management plan
- Ordering medications or tests
- Communicating clinical recommendations
- Performing other related professional work
The work must relate directly to the patient’s online clinical service. Administrative tasks should not be treated as clinical E/M work.
CPT 99423 Documentation Requirements
Strong documentation supports both medical necessity and coding accuracy.
Providers should clearly document:
- Patient’s online request
- Clinical concern or condition
- Provider’s evaluation
- Relevant clinical findings
- Management decisions
- Professional time
- Communications during the service period
- Orders, prescriptions, or follow-up instructions when applicable
The medical record should make the reported service understandable to another reviewer.
When Should Providers Avoid CPT 99423?
Providers should not report the code simply because a patient sends multiple messages. The communication must meet the requirements for an online digital E/M service. Administrative messages, appointment scheduling, and billing questions do not automatically qualify.
Providers should also review applicable bundling and reporting restrictions. Related services during the same period may affect separate reporting.
CPT 99423 and E-Visit Billing
An e-visit billing guide should distinguish clinical online services from administrative communication. Providers should first confirm that the patient initiated a qualifying service. They should then determine the applicable time tier. The e-visit billing guide process should also include documentation review before claim submission.
CPT 99423 Reimbursement Rate
The 99423 CPT code does not have one universal reimbursement amount for every payer. Medicare payment can depend on the applicable fee schedule and locality. Commercial insurers may use different reimbursement policies.
Providers should verify current payer rules before quoting a specific reimbursement amount. Billing teams should also confirm whether payer-specific requirements apply.
Medicare Billing for CPT 99423
Medicare recognizes online digital E/M services for qualifying established patients. Providers should confirm current Medicare requirements before submitting claims. Documentation should support patient initiation, clinical necessity, and the required professional work. Medicare policies can change, so billing teams should use current CMS guidance.
Common CPT 99423 Billing Mistakes
Several mistakes can create claim problems:
Reporting the Wrong Time Tier
Do not report 99423 when documented time remains below 21 minutes.
Counting Administrative Work
Scheduling and billing communication should not automatically count toward clinical time.
Weak Documentation
Missing time or clinical details can make the claim difficult to defend.
Ignoring Payer Rules
Commercial payer requirements may differ from Medicare rules.
Treating Every Portal Message as an E/M Service
A patient message does not automatically qualify for online digital E/M billing.
How Providers Can Improve Billing Accuracy
Providers should establish a consistent workflow for online digital services. First, identify patient-initiated qualifying requests. Next, track professional time during the applicable period. Document the clinical work as it occurs. Then select the time tier supported by the record. Billing teams should review payer requirements before claim submission.
FAQs About CPT 99423
What is CPT 99423?
CPT 99423 is an online digital E/M service for established patients. It requires at least 21 minutes of cumulative professional time.
How many minutes are required for CPT 99423?
The service requires 21 minutes or more of qualifying professional time. The time applies across a period of seven days.
What is the difference between 99422 and 99423?
99423 vs 99422 mainly depends on cumulative professional time. 99422 covers 11–20 minutes, while 99423 requires 21 minutes or more.
Is CPT 99423 a video visit?
No. It represents an online digital E/M service. It does not require the traditional real-time video format.
Who can report CPT 99423?
Eligible physicians and qualified healthcare professionals may report the service when all applicable requirements are met.
Does Medicare reimburse CPT 99423?
Medicare can reimburse qualifying online digital E/M services. Providers should verify current Medicare and locality-specific requirements.
Final Thoughts
The 99423 CPT code gives providers a billing option for higher-time online digital E/M services. Its key requirement is at least 21 minutes of qualifying professional work. Providers should also confirm patient status and service initiation.
Accurate time tracking protects coding accuracy. Clear documentation supports medical necessity and claim review. Billing teams should also verify current payer requirements before submission.
For medical practices, consistent digital-service workflows can reduce coding errors. Medi Remote can also support healthcare teams with reliable medical billing and remote administrative services.
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