Have you ever had a patient take more time with the provider than they were scheduled for? Do you understand which codes to report and the rules that govern them to allow for better reimbursement?

Prolonged Service codes were created just for that reason but you must carefully follow the documentation and coding guidelines to avoid problems. These “add-on” codes are reportable only when an Evaluation and Management code has been reported as the primary code. There are three types of Prolonged Service codes (see below) but here we will review the rules pertaining to codes 99354-99357.

There are three sets of codes for reporting various types of prolonged E/M services:

  • Prolonged Service with Direct Patient Contact  (99354-99357)
  • Prolonged Service without Direct Patient Contact  (99358-99359)
  • Prolonged Clinical Staff Services with Physician or Other Qualified Health Care Professional Supervision  (99415-99416)

CPT codes for Prolonged Service with Direct Patient Contact  (99354-99357) include the following subcategories:

Office/Other Outpatient Setting (direct face-to-face services)

99354   First hour

99355   Each additional 30 minutes beyond the first hour

Inpatient Setting (direct face-to-face services)

99356   First hour

99357   Each additional 30 minutes beyond the first hour 

Prolonged Service Codes Are Add-On Codes

All of these codes are considered “add-on” codes and should only be reported after a primary Evaluation and Management service code has been reported. Time and Direct face-to-face contact are the two main criteria for determining whether one or both codes are reported. Documentation must identify the total time (start and stop times are preferred by many payers) spent in direct, face-to-face contact with the patient (either continuous or accumulated) as well as what was discussed, counseled, or coordinated with the patient. If time is accumulated, then documentation of what the patient was being monitored for (by the provider) should be documented in the medical record.

Rule of Halves

The rule of halves is applicable to specific timed codes. It indicates that as long as half of the assigned time is completed, the code can be reported. For example, to qualify for 99354 (which has an assigned time of 60 minutes), the provider only has to complete the first 30 minutes. Anything less than 30 minutes doesn’t qualify. However, the second add-on code 99355 (which has an assigned time of 30 minutes), requires the full 60 minutes of the first code to be completed followed by an additional 15 minutes to reach the halfway mark for add-on prolonged code 99355.

Direct Face-to-Face Defined

Direct face-to-face is defined by the American Medical Association vaguely for office/outpatient as face-to-face contact with the physician or other qualified healthcare professional and in the hospital or nursing facility as “includes additional non-face-to-face services on the patient’s floor or unit in the hospital or nursing facility during the same session.” However, Medicare is far more deliberate in their definition:

Office/Other Outpatient: The Medicare Claims Processing Manual states, “In the case of prolonged office services, time spent by office staff with the patient, or time the patient remains unaccompanied in the office cannot be billed.”

Hospital Inpatient or Nursing Facility: The Medicare Claims Processing Manual states, “time spent reviewing charts or discussion of a patient with house medical staff and not with direct face-to-face contact with the patient, or waiting for test results, for changes in the patient’s condition, for end of a therapy, or for use of facilities cannot be counted as direct, face-to-face time.”

Time Defined 

Total time should be calculated with start and stop times (especially if the payer specifies they are required). In the case of accumulated time, (where face-to-face time is not continuous) the provider should document a total face-to-face time in the medical record. A total time (including start and stop times) should be documented in the medical record for patients receiving prolonged evaluation and management services in the Office or Other Outpatient setting.  

TIP:  Time-based E/M services must identify what the patient was counseled on or about or what was coordinated. It does not have to be detailed, but must be sufficient enough to stand up to scrutiny and inquiry. Simply summarize (with enough detail to make it individual to the patient) what was discussed or done during that time.

A very generic statement, such as, “A total of 75 minutes was spent counseling and coordinating care for the patient” would not suffice. The note should identify what was counseled, discussed, coordinated, or monitored that required the provider’s presence and services. It does not have to be detailed, but the rule of thumb should be to provide enough information years after the service, when audits commonly occur, a provider could look at the note and defend it because there is enough detail to recall what was done.

Putting It All Together

When the provider has documented time spent face-to-face with the patient that goes above and beyond the “norm,” he/she may review the service to see if it qualifies for prolonged evaluation and management service codes by following these steps: 

Step 1:

The encounter must be scored (either by time or key components) and coded with an appropriate E/M service code. If based on components, it means the documentation requirements for history, exam, and medical decision making have determined the level of E/M service. If based on time, the level of E/M service meeting the time requirement (new or established; initial or subsequent) should be selected.

TIP: Check your specific payer rules for specific guidelines that may vary from general CMS guidelines. For example, CGS Medicare, among other payers, will only allow a prolonged E/M code to be added to the highest level of service within the specific E/M code set it applies to such as 99215 or 99205 and not a lower code like 99212 or 99203. Additionally, some payers require start and stop times to be documented. 

Step 2:

Once an E/M code has been assigned, identify the typical time associated with that code and deduct it from the total time spent face-to-face with the patient. The remaining time will be used to calculate eligibility for adding a prolonged E/M service code.


1.  In the office setting, the E/M service, based on component coding, was 99213, which carries a typical time of 15 minutes. The total face-to-face time spent with the patient was 60 minutes. Deduct the 15 minutes from the total time of 60 minutes, which leaves 45 minutes remaining. This is the time used to determine whether or not the service qualifies for Prolonged Services.

If this was done for CGS, however, or a payer that requires the highest level of E/M service within the category be reported before adding a prolonged E/M code, the same 60-minute E/M service (as noted above) would be first reported using 99215 (with a 40 minute typical time), leaving a remaining 20 minutes of prolonged service time, which would not eligible for addition of a prolonged E/M code, as the rule of halves requires a minimum of 30 minutes (of the 60 minute typical time) in order to be eligible for reporting it.

2.  In the facility setting, an initial patient’s E/M service (based on time), was documented at 92 minutes provider time spent at the patient's bedside and on the patient's floor or unit in the hospital or nursing facility on a given date, providing prolonged E/M or psychotherapy services to the patient. This qualifies for 99223, which carries a typical time of 70 minutes. The total face-to-face time documented in the record was 92 minutes. Deduct the 70 minutes from the 92 minutes, which leaves 22 minutes remaining. This is the time used to determine whether or not the service qualifies for Prolonged Services.

Step 3:

Determine if the time remaining qualifies for application of the first Prolonged Service code. Using the above examples, we’ve determined the following:

  1. After deducting the E/M service time from the total time from 99213 (15 minutes) another 45 minutes remained. Because more than half of the 60-minute time requirement was achieved, the service qualifies for 1 unit of Prolonged Service 99354.
    • or in the case of CGS, the service would be reported as 99215 (40 minutes) with no eligibility for a prolonged E/M service code, as that would leave only 20 minutes to apply towards a prolonged E/M service code and a minimum of 30 minutes is required. 
  2. After deducting the E/M service time (99223 70 minutes) from the total time of 92 minutes, 22 minutes remained. Because at least half of the 60-minute time requirement was not achieved, it does not qualify for a Prolonged Service code. This extra 22 minutes would simply be considered included in the initial E/M service.

Step 4:

After the first Prolonged Service code has been achieved, determine if there is any additional time that may be considered towards an add-on code (99355, 99357) as well. Using the examples above, we’ve determined the following:

  1. Code 99354 has an associated time of 60 minutes. The rule requires at least half (or 30 minutes) be spent to qualify for one unit of this code. However, in order to qualify for the next code (99355) the full 60 minutes for code 99354 must be met and an additional 15 minutes (half of the 30 minutes) must be met to report 99355. This service does not qualify for 99355. The codes that should be reported for this service would be 99213 and 99354 or in the case of CGS Medicare, only 99215 would be reported.
  2. Code 99356 requires a minimum of 30 minutes but as seen in Step 3, didn’t qualify because there were only 22 minutes that could be applied to it. Because it did not qualify for 99356, it cannot even be considered for 99357 and only 99223 would be reported.

An example in which the second add-on code would qualify would be as follows:

An established patient returned to our office for a refill of pain medications and to discuss the pathology and imaging findings related to her recently diagnosed malignant neoplasm of the left breast. A total of 148 minutes were spent, face-to-face, counseling the patient regarding her prognosis, surgical and nonsurgical options, risks, complications, alternatives, and recommended oncologists. Based on face-to-face time alone, the following codes would be reported: 

99215 (40 minutes)

99354 (60 minutes)

99355 (30 minutes)

99355* (18 minutes)

*(The 99355 would simply be reported with two (2) units) 

Coding Based on Accumulated Time (not continuous)

An 8-year-old boy, established patient, presented to our office for an allergic reaction to a wasp sting of the right temple yesterday at noon. His mother reports giving him 25 mg of Benadryl within 10 minutes of the sting and washing the sting site with warm soapy water. She reports no symptoms until this morning, when he awoke with severe facial swelling indicating a delayed but possibly severe allergic reaction.

The provider documents a level of service to include detailed history and examination as well as a moderate complexity decision making. It was decided to administer an injection of adrenaline and monitor the patient. Additional treatment of Benadryl and antibiotics were administered as well. The provider was in and out of the patient room monitoring the patient and discussing findings with the mother. Total face-to-face time was 70 minutes.

Coding: The provider reported 99214 and 99354. There was not enough time to qualify for 99355.

Sometimes using a Time Table makes identifying eligible services easier. The table identifies the E/M service type and level with the typical time and the last two columns identify the time required to report a single unit of each add-on code. Again, in the case of payers that require the highest level of E/M code based on time be reported first, codes 99201-99204, 99211-99214, 99221-99222, 99231-99232 would be eliminated from the following table and a prolonged E/M code would only be eligible if the time exceeded the time requirement for 99205, 99215, 99223, and 99233 with at least half (30 minutes) of the prolonged E/M service time also met. 

Prolonged Evaluation and Management Service Threshold Times

E/M Code

Typical Time

for E/M

Threshold Time



Threshold Time for Both

99354, 99355 or 

99356, 99357