CPT 99354: Prolonged Service, First Hour
Prolonged evaluation and management service in the outpatient setting requiring direct patient contact beyond the usual service, first hour. An add-on code billed with the primary E/M service.
Why CPT 99354 Claims Get Denied
Claims billed under CPT 99354 are frequently denied or downcoded for the following reasons. Understanding these patterns helps your practice reduce denial rates and recover revenue faster.
Time documentation does not support prolonged services
Primary E/M code time threshold not met
Billed without a qualifying primary E/M code
Total time does not exceed the threshold for the base code
Billing Tips for CPT 99354
This is an add-on code — must be billed with a primary E/M code. The total time must exceed the maximum time threshold of the primary E/M code by at least 15 minutes. Document total face-to-face time including the base E/M time and extended time. Bill 99355 for each additional 30 minutes beyond the first prolonged hour.
Documentation Requirements
To support a clean claim for CPT 99354, your clinical documentation should include:
Total face-to-face time with patient
Start and end times of the encounter
Activities performed during extended time
Clinical justification for prolonged service
Billing of the primary E/M code
Reduce CPT 99354 Denials by 60%
RediClaim's pre-submission scrubber catches documentation gaps and coding errors before you submit, while the appeal generator handles denials that slip through.