Infusion & Hydration Billing & Coding Guide

What the CPT manual doesn't tell you about infusion, injection & hydration.

Table of Contents

Overview of Infusion CPT Codes
CPT Code Description
Time-Based Billing Rules
Essential Documentation Requirements
Modifier Guidelines for Infusions
Common Billing Mistakes & Audits

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Infusion and injection coding remains one of the most audited and misunderstood areas in outpatient and facility billing. Between time-based reporting rules, hierarchy guidelines, hydration requirements, and modifier usage, even experienced coders can make costly errors.

This 2026 Infusion & Injection Billing Guide breaks down everything you need to correctly report IV hydration, therapeutic infusions, sequential services, and concurrent infusions. Whether you work in emergency medicine, outpatient hospital, infusion centers, or physician-based clinics, this guide will help you:

Code initial vs. subsequent services correctly
Apply time rules accurately
Avoid duplicate billing errors
Use modifiers properly
Reduce audit risk

Coding Tip: You only get one "Initial" code per encounter. The hierarchy ( Therapeutic > Hydration) dictates which one "wins" the initial slot, regardless of the chronological order in which the bags were hung.