Pulmonology Coding Alert

Question: Could you explain the difference between “first hour” codes and “up to 1 hour” codes?

South Dakota Subscriber

Answer: Differentiating between “first hour” and “up to 1 hour” codes can be tricky, even for seasoned coders, and we’re happy to break down the distinctions.

CPT^® codes that feature “up to 1 hour” in their descriptors, such as 96365 (Intravenous infusion, for therapy, prophylaxis, or diagnosis (specify substance or drug); initial, up to 1 hour), cover procedures or services that cover any amount of time up to 60 minutes, including 31, 45, or the full 60 minutes. After the hour mark, you’d need another unit of the same code or an add-on code, if applicable.

The “first hour” CPT^® codes, such as 94644 (Continuous inhalation treatment with aerosol medication for acute airway obstruction; first hour), are restricted to procedures that last 60 minutes. After the first hour, you’ll assign an add-on code like +94645 (… each additional hour (List separately in addition to code for primary procedure) to report the additional time.

However, in order for you to report the additional hour, the provider is required to perform services past the midpoint of the hour, according to the CPT^® guidelines. In other words, the provider must perform services for 91 minutes to report two hours (60 minutes for the first hour + 31 minutes for the second hour).