Prolonged service proficiency

The coding and billing of prolonged services depend on the face-to-face time spent with the patient over and above the average.


For correct coding and optimum reimbursement, hospitalists must have a firm grasp on the nature and documentation requirements of prolonged evaluation and management (E/M) services. This challenging concept is often misunderstood, misapplied and underused. Failure to recognize, document and properly calculate prolonged services results in both underpayment and audit risks for non-compliance.

The coding and billing of prolonged services depend on the face-to-face time spent with the patient over and above the average time that the 2011 Current Procedural Terminology (CPT®) codes assign to the usual E/M service (see box at bottom for average times).

Photo by Comstock
Photo by Comstock.

Face-to-face time for inpatient and subsequent observation services is defined by the 2011 CPT® as “unit/floor time, which includes the time that the physician is present on the patient's hospital unit and at the bedside rendering services for that patient. This includes the time in which the physician establishes and/or reviews the patient's chart, examines the patient, writes notes, and communicates with other professionals and the patient's family.”

Under the description of Prolonged Physician Service with Direct (Face-to-Face) Patient Contact, the 2011 CPT® states, “Codes 99356-99357 are used to report the total duration of unit time spent by a physician on a given date providing prolonged service to a patient.” The time may be continuous or discontinuous.

Code 99356 is assigned for the first 30 to 60 minutes of prolonged physician service in the inpatient setting (including subsequent observation services). Billing for less than 30 minutes of prolonged service is not allowed. Code 99357 is assigned for each additional 30 minutes after the first 60. Since a unit of time is only attained when the mid-point is reached, 99357 cannot be used until 75 minutes of prolonged service have been provided (60 minutes for 99356 plus an additional 15 minutes—the mid-point for 99357). See the “Prolonged Service Codes” and “Examples” boxes on page 11 for more details.

So how do you calculate prolonged service time?

  • First, determine the total unit-time you spent with the patient during the day, whether the time was continuous or discontinuous.
  • Next, look up the average time assigned by the 2011 CPT® to the basic E/M service you rendered to the patient (see “Average Time” box, page 11).
  • The billable prolonged service time will be the difference between the total time and the time assigned by the 2011 CPT® to the basic E/M service provided (see “Examples” box, page 11).
  • Document the time involved in the medical record.

In summary, keep track of the on-unit time spent on each patient, and document it. Bill as prolonged service the time spent above and beyond the average time assigned by the 2011 CPT® to the basic E/M service provided on a given day.