Z Code Reporting for COVID-19

Updates from 1/19/21 in green font.

Updates from 7/27/20 in red font.

Just a few reminders on coding for COVID-19 when the test results are NOT positive. Obviously any positive test result documented in the record for COVID-19 would be coded to U07.1, COVID-19.

If the facility does a COVID-19 test, and test is negative, do I need a diagnosis code?

The answer is yes, you will report a Z-code. For any patient receiving a COVID-19 test, if negative, there MUST be a Z-code to describe why the test was taken. (Test negative for COVID-19 and MD does not override negative results).

The codes to use were described in the original COVID19 FAQ prior to the release of the FY2021 OCG In addition, on 7/24/20 HIA has received an answer back to a letter inquiring if Z20.828 (Z20.822 after 1/1/2021) should be used for ALL testing for COVID-19 with negative test results, regardless of symptoms or no symptoms, documented exposure or not.  AHA has responded that “It was advised that it is appropriate to assign code Z20.828, Contact with and (suspected) exposure to other viral communicable diseases (Z20.822 after 1/1/2021), as an additional code when a patient is screened or tested (pre-operatively) for COVID-19 and the test is negative.”   Also they stated that per guideline I.C.21.c.1 Contact/Exposure, Z20 codes may be used for patients who are in an area where a disease is epidemic and there is concern that the patient may have been exposed to the disease. Code Z20.828 (Z20.822 after 1/1/2021) may be assigned without explicit documentation of exposure or suspected exposure to COVID-19. The patient does not have to exhibit sign and symptoms associated with COVID-19.  See below OCG for FY2021:

*In early July, CDC released the FY2021 ICD-10-CM Official Guidelines for Coding and Reporting effective October 1, 2020. In the below you will see that the advice has changed from what was provided in the AHA FAQ document.    Please see (f) Screening for COVID-19 below. The advice states that now for screening for COVID-19 and negative test result, regardless of symptoms, should be coded Z20.828 and not Z11.59 (Z11.52 after 1/1/2021) or Z03.818 as these are considered screening codes.  The reason is that we are in a COVID-19 pandemic and the screening codes would no longer apply.  Some facilities have decided to implement the below advice now.  HIA had sent a letter to AHA regarding this information in June, that was also sent to the EAB and we are still awaiting reply.

ICD-10-CM Official Guidelines for Coding and Reporting FY 2021 Page 31 of 126

(e) Exposure to COVID-19

For asymptomatic individuals with actual or suspected exposure to COVID-19, assign code Z20.828, Contact with and (suspected) exposure to other viral communicable diseases. (Z20.822 after 1/1/2021)

For symptomatic individuals with actual or suspected exposure to COVID-19 and the infection has been ruled out, or test results are inconclusive or unknown, assign code Z20.828, Contact with and (suspected) exposure to other viral communicable diseases (Z20.822 after 1/1/2021). See guideline I.C.21.c.1, Contact/Exposure, for additional guidance regarding the use of category Z20 codes.

If COVID-19 is confirmed, see guideline I.C.1.g.1.a

(f) Screening for COVID-19

During the COVID-19 pandemic, a screening code is generally not appropriate. For encounters for COVID-19 testing, including preoperative testing, code as exposure to COVID-19 (guideline I.C.1.g.1.e).

Coding guidance will be updated as new information concerning any changes in the pandemic status becomes available.

Where in the record is it?

Coders will need to research their facility’s record on where to find orders for COVID-19 testing, laboratory results for COVID-19 and documentation of results. Usually test results are documented in the progress notes, but not always.  Each facility is unique in where COVID-19 test orders are so be sure you know where they are.  Coders should really be looking for these orders and tests as more and more facilities are testing patients for COVID-19. In some electronic health records, the coder can search by typing in “COV” in the search box and every instance of documentation of it in the record will come up for review.

COVID-19 Code Validation

Some facilities are validating the coding of every COVID-19 patient.  If so, the coder must be sure to follow facility protocols on pending or referring the record for review.

History of COVID-19

If a patient has a history of COVID-19, and has no signs, symptoms and no manifestations of COVID-19 any longer, assign the history code Z86.19, Personal history of other infectious and parasitic diseases (Z86.16 after 1/1/2021)There is not a timeframe for the history code so coders will need to review documentation carefully.

Follow-up visits after COVID-19 infection has resolved

(j) Follow-up visits after COVID-19 infection has resolved

For individuals who previously had COVID-19 and are being seen for follow-up evaluation, and COVID-19 test results are negative, assign codes Z09, Encounter for follow-up examination after completed treatment for conditions other than malignant neoplasm, and Z86.19, Personal history of other infectious and parasitic diseases.

Antibody Testing for COVID-19 Only

For an encounter for antibody testing that is not being performed to confirm a current COVID-19 infection, nor is a follow-up test after resolution of COVID-19, assign Z01.84, Encounter for antibody response examination.

Follow the applicable guidelines above if the individual is being tested to confirm a current COVID-19 infection.


Below is the advice used PRIOR to this directive we received from AHA:

Three Z codes to choose from:

These codes were described in the original COVID19 FAQ prior to the release of the FY2021 OCG: 

Z20.828, Contact with and (suspected) exposure to other viral communicable diseases is assigned when a patient exhibits signs and symptoms of COVID-19 and COVID-19 is suspected, and COVID-19 test is negative.  The symptoms or reason for symptoms would be coded followed by the Z20.828 code.

Z03.818, Encounter for observation for suspected exposure to other biological agents ruled out is assigned when there is NO symptoms or signs of COVID-19 however the patient was documented as being exposed to COVID-19.  Examples include the patient coming in contact with another patient with COVID-19 or some other type of exposure.  The key here is that there is exposure or suspected exposure to COVID-19.  When the test is negative assign Z03.818 to show that the patient was exposed to COVID-19, had no symptoms, and the testing was negative.

Z11.59,  Encounter for screening for other viral diseases is used for a patient who presents for COVID-19 testing and has no symptoms and no exposure, and test is negative.  Early on in the pandemic, only patients with symptoms and exposure were being tested for COVID-19.  They had to meet CDC requirements for testing.  As test kits have become more available, many more patients are being tested without symptoms and without known exposure.  We know of one facility that is testing EVERY PATIENT so there would be a Z code on every patient, testing negative, depending on circumstances. If no symptoms with no exposure documented then it would be Z11.59.  These are typically considered screenings for COVID-19. Coders may also see patents screened before outpatient surgeries, or before going to a nursing home.


Health Information Associates offers medical coding services, medical auditing services, and clinical documentation audit services for hospitals, ambulatory surgery centers, physician groups and other healthcare entities in the United States.


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The information contained in this post is valid at the time of posting. Viewers are encouraged to research subsequent official guidance in the areas associated with the topic as they can change rapidly.

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