Internal Medicine CPT Codes A Complete Guide

Last Updated on September 23, 2025

Internal Medicine sits at the center of adult healthcare. Internists are often the first point of contact for patients managing conditions like diabetes, hypertension, asthma, and cardiovascular disease. They provide ongoing care across office visits, preventive screenings, chronic care coordination, and even hospital consults.

In this environment, CPT coding is more than just compliance, it’s the foundation of financial health. Each encounter must be translated into the correct code so that payers reimburse fairly and practices sustain their revenue cycles.

Understanding CPT codes in Internal Medicine means recognizing both the bread-and-butter office visit codes and the complex codes that support care coordination, hospital admissions, and advanced planning. This guide walks through Internal Medicine CPT codes from core to complex, showing how they drive reimbursement and where practices often miss revenue opportunities.

Core Codes: Office and Outpatient E/M

The backbone of Internal Medicine billing lies in Evaluation and Management (E/M) codes for office visits.

• 99202–99205 → New patient office visits
• 99211–99215 → Established patient office visits

Since the 2021 CPT guideline changes, code selection is determined by either:

• Medical Decision Making (MDM), or
• Total time spent on the day of the encounter.

Example:

• A diabetic patient with hypertension and medication adjustments → 99214 (moderate complexity).
• A stable patient for routine BP check with no changes → 99213.

Many internists default to 99213, even when documentation supports 99214. This underbilling results in lost revenue. According to the AMA, proper use of MDM can improve coding accuracy and reduce denials (AMA CPT E/M Guidelines).

Expanded Codes: Preventive and Annual Wellness

Preventive visits are coded separately from problem-oriented office visits. They are critical because payers often cover them fully, but miscoding can lead to denials.

• 99385–99387 → Preventive visits for new patients
• 99395–99397 → Preventive visits for established patients
  

Example:

• Patient comes for an annual wellness exam → 99397.
• Same patient also reports chest pain → Bill 99397 + 99213 with modifier -25 to distinguish the problem-oriented visit.

This area is heavily scrutinized. Without clear documentation, payers may deny one of the visits. Internists who code both properly not only protect reimbursement but also show compliance with preventive care mandates under Medicare and commercial plans.

Also read – CPT Codes for Pathology

Advanced Codes: Chronic and Transitional Care

Internists manage the majority of patients with chronic diseases like COPD, CHF, and diabetes. Yet chronic care codes remain some of the most underutilized in Internal Medicine.

• 99490 → Chronic Care Management (20 minutes, clinical staff)
• 99439 → Each additional 20 minutes
• 99491 → Chronic Care Management (30 minutes, physician or qualified professional)
• 99495, 99496 → Transitional Care Management (post-hospital discharge follow-up)

A patient discharged after pneumonia requires a 30-day follow-up. Billing 99495 ensures internists are reimbursed for coordinating care and reducing readmission risk.

CMS continues to encourage the use of these codes to support value-based care models. According to CMS data, practices that adopt CCM see better patient outcomes and more consistent revenue.

Complex Codes: Hospital and Inpatient Care

Some internists also manage hospitalized patients. These encounters are more complex, requiring specific CPT codes:

• 99221–99223 → Initial hospital care
• 99231–99233 → Subsequent hospital care
• 99238–99239 → Discharge services

Example:

• Admission for pneumonia with moderate MDM → 99222.
• Daily follow-up visit with medication adjustments → 99233.
• Discharge summary requiring >30 minutes → 99239.

Because inpatient claims are high-value, they are also highly audited. Internists must carefully document MDM elements and time spent.

Specialized Codes: Emerging and Overlooked Opportunities

At the top tier of Internal Medicine coding are specialized codes that reflect evolving care delivery models.

• 99497, 99498 → Advance Care Planning (ACP). Supports billing for documented discussions about end-of-life or serious illness planning.
• G2211 → Add-on code for visit complexity, reintroduced in 2024–25, intended to capture the ongoing complexity of primary care.
• 99212–99215 with POS 10 → Telehealth visits provided from the patient’s home. Telehealth remains reimbursable in 2025 for many payers, particularly for chronic care follow-ups.

These codes are often overlooked but represent important revenue streams. They also align Internal Medicine practices with value-based care and patient-centered outcomes.

Why the Core-to-Complex Approach Works

Breaking Internal Medicine coding into layers helps practices:

• Protect revenue from high-volume office visits.
• Capture opportunities in preventive and chronic care that are often underbilled.
• Stay compliant with complex hospital codes.
• Unlock incremental revenue with specialized services like ACP and telehealth.
  

Rather than viewing CPT coding as a checklist, internists can see it as a strategic progression, from core services to complex encounters, that ensures financial stability and compliance.

Internal Medicine coding demands both breadth and depth. By mastering core E/M codes, expanding into preventive and chronic care management, and adopting specialized codes, internists can ensure they are fully reimbursed for the comprehensive care they provide.

With payer scrutiny increasing and care models evolving, the ability to code from core to complex is what keeps Internal Medicine practices financially strong and patient-focused.

FAQs on Internal Medicine CPT Codes

What is the difference between 99213 and 99214 in Internal Medicine?
99213 is used for established patient visits with low complexity or minimal management, while 99214 is for visits with moderate complexity and more detailed medical decision making. Correct documentation is essential to justify the higher-level code.

Can Internal Medicine practices bill for both chronic care management and office visits?
Yes. Chronic Care Management (99490, 99491) covers non-face-to-face care coordination over a calendar month, while office visit codes (99212–99215) cover in-person or telehealth visits. Both can be billed if documentation supports them.

How should preventive visits be billed if the patient has a new medical issue?
Preventive visits (e.g., 99397) should be billed separately from problem-oriented visits (e.g., 99213) when both services are performed on the same day. A modifier -25 must be added to the problem-oriented visit to avoid denials.

Are hospital admission and follow-up visits billed differently?
Yes. Initial hospital admissions are billed with 99221–99223, while daily progress notes use 99231–99233. Discharge services have their own codes (99238, 99239) based on time spent.

What new CPT codes or changes affect Internal Medicine billing in 2025?
The CMS add-on code G2211 for visit complexity has been reinstated, and telehealth visits with POS 10 continue to be reimbursed by many payers. Internists should also monitor evolving payer rules for chronic care and preventive codes.