Home and Outpatient Services—Let’s Get it Straight

New billable CPT® codes for monitoring patients who are taking blood-thinning medications.

In 2018, CPT® deleted codes 99363 and 99364 and replaced them with codes 93792 and 93793. There are two important things to know about coding for international normalized ratio (INR) monitoring, also known as a “protime check” (PT).

First, the new codes apparently are not on everyone’s radar, as I am still seeing practices ask me about them, now well into 2019, and they are wondering why nurse visits coded using 99211 are being denied.

Second, I think it is important, as a healthcare professional and coder, to understand what this medicine is and how it is used so you can code it effectively.

These codes are for monitoring patients who are taking blood-thinning medications such as Coumadin. You may hear these also called “Coumadin checks.” Millions of people take it daily to prevent blood clots. Coumadin is actually derived from a chemical called coumarin. Coumarin is an active ingredient used in rat poison and was used as a commercial pesticide. The way it works is that it blocks the vitamin K in the coagulation cascade. Vitamin K is necessary to help the blood clot properly. For example, if you cut your finger, within a few minutes, the bleeding will stop, as long as you have adequate platelets, vitamin K, and all of the other necessary ingredients.

When people have a heart attack or stroke, it is due to a blood clot. In those situations, we know that their blood is too thick. This will automatically cause them to be at a higher risk of having another heart attack or stroke. That’s why physicians order Coumadin to act as a blood thinner by blocking the vitamin K pathway. Coumadin has been used for decades because it is cheap and effective. However, sometimes it’s too effective, and that is where the monitoring is necessary. People who are on this medicine or other blood thinners often complain about excessive bleeding and bruising, even from simple injuries.

For example, if somebody bumps their knee at the edge of a table, they may not consider this a serious injury. But some patients end up in the ER hours later because their knee swells up with large amounts of blood, which then have to be drained out. So blood thinners definitely save lives, because they reduce the risk of heart attack and stroke. However, the downside is that the blood is just too thin at times.

People who have been on Coumadin for years can still have some side effects: spontaneous bleeding from the gums, bleeding in urine, etc. If someone on blood thinners is scheduled for a wisdom tooth extraction, shoulder surgery, or any type of invasive procedure, the surgeon or dentist will want to avoid excessive bleeding. In that case, the surgeon will notify the PCP or cardiologist that they are scheduled for surgery and that the patient needs to stop Coumadin (and note when to resume it). There are other risks involved with the monitoring of this medication for patients, but you get the general idea on why it is so important to have a schedule of monitoring and to get consistent payment for it.

Here are the billable codes: 93792, 93793:

• 93792 Patient/caregiver training for initiation of home international normalized ratio (INR) monitoring under the direction of a physician or other qualified healthcare professional, face-to-face, including use and care of the INR monitor, obtaining blood sample, instructions for reporting home INR test results, and documentation of patient’s/caregiver’s ability to perform testing and report results
• 93793 Anticoagulation management for patients taking warfarin, must include review and interpretation of a new home, office, or lab international normalized ratio (INR) test results, patient instructions, dosage adjustment (as needed), and scheduling of additional test (s), when performed

There’re a few things of note to consider about these codes.

• 93792 is the code used for patients who test their INR at home, rather than going to the laboratory. Prior to starting this home testing, the patient needs to understand how to use the test reliably. This instruction and training is now a covered service. Notice that for patient/caregiver instruction and training, there are no work relative value units (RVUs) assigned. This is work that would typically be done by clinical staff or case managers.

The more routine code you will see reported is the following:

• 93793 is payment for managing patients taking warfarin. It includes the review and interpretation of a new test done in the home, office, or lab. This code does have work RVUs, recognizing that it is physician/NP/PA work to interpret the lab results, make a dosing adjustment if needed, and schedule additional tests, again, if needed. The dosage does not need to be changed in order to report 93793. It is for a new test result.

With Coumadin, you have to check the INR or PT value at least monthly. Often people are checked more frequently, especially because Coumadin can interact with antibiotics, anesthesiology, and even certain vegetables. (There are other blood thinning medications that do not have the same monitoring requirements as Coumadin, such as aspirin, Plavix, Eliquis, and Xarelto, because you don’t have to monitor the patient’s blood, but they tend to be pricey).

If the blood draw is performed in the physician’s office and processed in their in-office lab, can the 85610 (Prothrombin time) path/lab test be coded, as well as the 93793 code? Yes. Both codes may be reported.

If the criteria for the reporting of the 93793 is met, and performed from an outside lab, and if the patient is not seen face-to-face in the office but is contacted with “..instructions, dosage adjustments (as needed), and scheduling of additional test(s),” this can be coded with POS 11 as long as a qualified healthcare professional is supervising the delivery of the service by the healthcare clinician. POS would still be 11.

CPT says, “do not report 93793 on the same day as an E&M (evaluation and management) service.”

So, if the INR is done on the day of the visit and the physician/NP/PA interprets the result and gives the patient dosage instructions, do not report 93793 in addition to the E&M. This is a separate service that is not part of the E&M encounter that day. If the E&M service is provided, then all INR testing and discussions would be included in the service.

CPT also states not to report either code during the service time of chronic care management (CCM) or transitional care management (TCM, 99487, 99489, 99490, 99495, 99496). “During the service period” would mean during any calendar month of reporting CCM and during the 30-day post discharge period, if billing TCM.

This is good news. You are probably already providing this service, but now you should consistently get reimbursed for your efforts.

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