How to Bill 99203 and 99204 Correctly?

Billing 99203 and 99204 can feel confusing, especially with evolving E/M guidelines. Both are new patient visit codes, but the required time, MDM level, and documentation differ. Selecting the wrong code can reduce reimbursement or create audit risk.

This guide explains the differences, shows you when to use each code, and gives you practical rules you can use in daily clinical practice.

What Is CPT 99203?

CPT 99203 is a new patient office or outpatient visit that requires a low level of MDM or 30–44 minutes of total time on the date of the encounter.

This code is common for straightforward or low-complexity visits such as routine consultations, minor symptoms, stable conditions, or simple treatment plans.

Time and MDM Requirements for 99203

Time Range:

• 30–44 minutes total time spent on the date of the encounter.

Medical Decision Making:

• Low complexity MDM.

• Typically involves 1 stable chronic illness, an acute uncomplicated issue, or straightforward diagnostic work.

Risk Level:

• Low risk of complications or morbidity.

Documentation Elements Required for 99203

Your note must support either time or MDM:

If billing by time, document:

• Start/stop time OR

• Total time spent

• Activities performed (reviewing records, exam, counseling, documentation)

If billing by MDM, document:

• Number and complexity of problems

• Data reviewed

• Risk level (low)

Practical example:
"Patient presents with mild abdominal discomfort for 2 days… Low complexity workup and conservative treatment…"

What Is CPT 99204?

CPT 99204 is a new patient visit that requires a moderate level of MDM or 45–59 minutes of total time.

Use this code when the visit involves multiple problems, uncertain diagnoses, moderate risk decisions, or extensive data review.

Time and MDM Requirements for 99204

Time Range:

• 45–59 minutes total time.

Medical Decision Making:

• Moderate complexity.

Common scenarios:

• Worsening chronic condition

• Acute illness with systemic symptoms

• Prescription drug management

• Reviewing external notes or multiple test results
  
  

When to Use 99204 

Use 99204 when the visit includes:

• Moderate risk decisions

• Multiple new or chronic problems

• Uncertain diagnosis requiring additional work

• Prescription drug management

• Data review from outside sources

• Need for close follow-up or intensification of therapy

Example scenario:
A newly diagnosed diabetic patient requiring medication initiation, labs, education, and risk discussion.

Audit Risks 99204 (Overcoding Red Flags)

99204 is highly audited. Common triggers include:

• Documentation shows simple problems but 99204 is billed.

• No evidence of moderate risk decisions.

• No external data review or complex work documented.

• Time not clearly supported.

• Frequent use of 99204 for routine visits.

Protect yourself by documenting exact thought processes, risk discussions, and any external data you reviewed.

99203 vs 99204 — Key Differences

Choosing between these two codes depends on MDM level and time.

Comparison Table: Time, MDM, Complexity

“Level of Risk” Differences Explained

99203 Risk:

• Stable conditions

• Conservative treatment

• No prescription drug management

99204 Risk:

• Prescription drugs

• Side-effect monitoring

• Risk of exacerbation

• Need for diagnostic testing with risk

Documentation Requirements (99203 vs 99204)

Accurate documentation is the foundation of correct billing. Payers focus on whether your note supports the complexity or time billed.

What Payers Look For in Notes

• Clear problem list

• Your clinical thought process

• Tests reviewed or ordered

• External data review

• Risk discussion

• Medication counseling

• Total time if time-based billing is used

Sample Documentation Snippet for Both Codes

99203 Example:
“Patient presents with mild intermittent headaches. No red flags. Neuro exam normal. Recommended hydration, OTC analgesics, and observation. Low-risk plan.”

99204 Example:
“Patient with newly diagnosed hypertension. Reviewed prior ER notes and labs. Started antihypertensive medication. Discussed risks, monitoring, and follow-up.”

EHR Workflow Tips for Faster Compliance

• Use structured templates for MDM.

• Preload problem list and reconcile accurately.

• Add quick-select phrases for data review.

• Include auto-calculated time fields.
  
  

Billing Guidelines for 99203 and 99204

The correct code depends on whether time or MDM is more clearly supported.

Medicare-Specific Considerations

• Medicare accepts time-based billing or MDM, but notes must be consistent.

• Time includes pre-visit and post-visit work.

• Ensure telehealth rules match CMS guidelines.
  
  

Commercial Payer Variations

Some commercial plans require:

• Proof of external data review

• Electronic documentation for time

• Specific modifiers for telehealth

• Prior authorization for certain services

RVUs and Reimbursement Impact

Approximate 2025 RVUs:*

• 99203: ~1.60 RVUs

• 99204: ~2.60 RVUs

Telehealth Billing for 99203 and 99204

Telehealth usage remains significant. Coding rules must be followed closely to avoid denials.

Modifier 95 Rules

Use modifier 95 for synchronous telehealth visits when payer policy requires it.

Document:

• Patient location

• Provider location

• Method of communication

• Consent for telehealth

In-Person vs Telehealth Documentation Differences

Telehealth must still capture:

• MDM elements

• Time (if used)

• Clinical reasoning

• All data reviewed

• Limitations of telehealth exam

Common Billing Mistakes to Avoid

Under-Documenting MDM

Your note must show the number of problems, data, and risk supporting the code.

Overcoding 99204

Bill 99204 only if documentation shows moderate complexity or 45–59 minutes.

Time Tracking Errors

Avoid stating time without describing activities.
Example: “49 minutes spent reviewing labs, counseling, and documenting.”

FAQs

1. Can I bill 99204 for a simple problem if I spent 45 minutes?
   Yes, if you clearly document total time and activities on the visit date.

2. Can 99203 and 99204 be billed via telehealth?
   Yes, when allowed by payer policy and modifier 95 is applied if required.

3. What is the key difference between 99203 and 99204?
   99203 is low complexity; 99204 is moderate complexity with more data and risk.

4. Does prescribing medication automatically mean 99204?
   No, but it generally increases risk toward moderate complexity.

5. Can I bill based on time and MDM together?
   No. Choose one method per encounter.

6. How do I avoid 99204 audit risk?
   Document external data review, risk discussions, and clinical reasoning.

7. Do payers accept templates?
   Yes, but they must be customized per patient.

8. Can I bill 99203 for chronic conditions?
   Yes, if complexity and risk remain low.

9. Does reviewing external notes increase MDM?
   Yes—it contributes to moderate data complexity.

10. How do I appeal denied 99204 claims?
    Submit detailed notes showing MDM elements or time justification.
    
    

Author Bio 

Written by a senior medical billing strategist with over 10 years of experience in U.S. physician coding, E/M compliance, and revenue optimization. Specializes in helping practices reduce denials and strengthen documentation accuracy.