Breaking Down the E/M Prolonged Service Guidelines 99358 and 99359 into Digestible Nuggets with Scenario Examples (Pt. 2 of 3)

by Mrs. Jay, Curriculum Director of Absolute Medical Coding Institute. 

Mastering Prolonged Services Coding 99358 and 99359: A Comprehensive Guide

Prolonged services coding 99358 and 99359 are essential tools for healthcare providers to accurately capture and bill for the additional time spent on patient care beyond the standard Evaluation and Management (E/M) services. In this blog post, we will explore the specifics of these codes, their appropriate usage, and tips for successful documentation.

Understanding Prolonged Services Codes 99358 and 99359

The codes 99358 and 99359 are used in conjunction with a primary face-to-face E/M service code to account for extended time spent on a patient’s care on a different day than the primary face-to-face service but related to it.

• 99358: Prolonged evaluation and management service before and/or after direct patient care; first hour.
• 99359: Each additional 30 minutes (List separately in addition to the code for prolonged service).

It is essential to remember that 99358 is a standalone code that must be billed in relation to a direct/face-to-face encounter, while 99359 is an add-on code that must always be billed in conjunction with 99358.

When to Use Prolonged Services Codes 99358 and 99359

Prolonged services coding should be used when a healthcare provider spends significantly beyond the usual service time for a specific E/M code. The additional time must meet the following criteria:

• Prolonged services apply only to non-face-to-face activities, such as reviewing records, communicating with other healthcare professionals, or counseling the patient’s family.
• The prolonged service must occur on a different day (before or after) than the related face-to-face encounter.
• Prolonged services of less than 30 minutes are not coded.
• Use 99358 when at least 30 minutes beyond the typical time is met (30 – 74 minutes).
• Use 99359 for each additional 30 minutes of prolonged time. For the final units of prolonged time, a minimum of 15 minutes must be met to use code 99359.
• The services rendered must be medically necessary and directly related to any face-to-face E/M encounter.
• 99358 may only be used once per date of service.
• 99359 may be used on any given date of service with 99358.
• Time is not required for the related face-to-face/direct E/M service.
• Codes 99358 and 99359 are applicable to physicians and Qualified Healthcare Professionals (QHPs).

Proper Documentation for Prolonged Services

Thorough documentation is crucial when billing for prolonged services to ensure accurate reimbursement and avoid potential audits. Key elements to include in your documentation are:

• The start and end times of the prolonged service.
• A detailed explanation of the additional services provided during the prolonged period.
• A clear description of the medical necessity for the prolonged service.
• Reference the primary face-to-face E/M service code with which the prolonged services are related.
• Clearly differentiate the prolonged service time from the time spent on the primary E/M service.
• Ensure the total time spent on the prolonged service is accurately documented, including start and end times.

Application to Practice

Scenario for 99358

Dr. Khan spent 45 minutes reviewing extensive medical records, laboratory results, and imaging studies for her patient, Mrs. Martinez, who has a complex medical history, before their scheduled office visit. This additional time was necessary to develop a comprehensive treatment plan tailored to Mrs. Martinez’s needs.

Code for the encounter?

Rationale: In this scenario, the physician is spending prolonged time before a related encounter (note this encounter is not on the same day as the face-to-face encounter, which is documented as upcoming). Also, the upcoming face-to-face encounter is not documented and thus has no time specifications or requirements. We are directed to code 99358 for the first hour of prolonged time. However, since the time is less than one hour, we can use code 99358 as long as a minimum of 30 minutes has been met.

Final Answer: 99358

Scenario for 99358 and 99359

Dr. Wang spent one hour and 45 minutes reviewing detailed medical records, consulting with other healthcare professionals, and coordinating a multidisciplinary care plan for Mr. Thompson, a patient with multiple chronic conditions, the day after an office visit with Mr. Stein.

Code for the encounter: ___________________________

Rationale: In this scenario, Dr. Wang spent one hour and 45 minutes of prolonged time on a date other than a related face-to-face encounter. The face-to-face encounter occurred the previous day, making this an eligible prolonged physician encounter. If we convert one hour of time to minutes, we have 105 minutes. Referring to the chart below, you are directed to code 99358 and 99359 twice. The first 60 minutes were coded with 99358, the next 30 minutes with 99359, and the final 15 minutes with 99359.

Final Answer: 99358, 99359 x 2

Conclusion

Prolonged services coding 99358 and 99359 are vital for healthcare providers to accurately bill for the extra time spent on patient care beyond the standard E/M services. By understanding the appropriate usage of these codes, maintaining thorough documentation, and following best practices for billing, healthcare providers can ensure they receive fair compensation for their extended efforts in patient care..

For more on Prolonged service read this article by AHIMA