Diagnosis Coding During COVID-19 Public Health Emergency

As coding and billing regulations continuously change, the content of this article may not be the most up-to-date information and is not intended to take the place of either the written policies or regulations. We encourage participants to review the specific regulations and other interpretive materials as necessary.

We’ve collected all the most asked COVID-19 billing questions from those that use our chargemaster and knowledge solutions, and from attendees of past webinars. We then categorized them to make answers easier to find. In this article, we’ll cover FAQs around diagnosis coding during COVID-19 public health emergency.

What diagnosis code should be used to bill for COVID-19 testing when there is no order from the provider?

Per the ICD-10-CM Official Coding and Reporting Guidelines, asymptomatic patients who are being screened for COVID-19 and have no known exposure to the virus, may be assigned a diagnosis code of Z11.59, Encounter for screening for other viral diseases. These same guidelines also advise the assignment of diagnosis code Z20.828, Contact with and (suspected) exposure to other viral communicable diseases, for patients who have actual exposure to someone who is confirmed or suspected (not ruled out) to have COVID-19. If the lab test is subsequently found to be positive for COVID-19 infection, diagnosis code U07.1, COVID-19, should be assigned, even if the patient was asymptomatic.(05/05/2020)

1ICD-10-CM Official Coding and Reporting Guidelines April 1, 2020 through September 30, 2020, Chapter 1, Section g, Subsections 1.d., 1.e., 1.f. and 1.g.

Do you have any advice for coding the COVID-19 lab tests in circumstances where the patient has been discharged before test results are available, and the physician doesn’t mention why the test was ordered?

The ICD-10-CM Official Coding Guidelines state that signs/symptoms associated with COVID-19 should be assigned when a definitive diagnosis has not been established. The guidelines further state that code Z20.828, Contact with and (suspected) exposure to other viral communicable diseases, should be assigned as an additional code for patients who have either an actual or a suspected contact with or exposure to someone who has COVID-19. If the lab test is subsequently found to be positive for COVID-19 infection, diagnosis code U07.1, COVID-19, should be assigned, even if the patient was asymptomatic.1 (05/06/2020)

1ICD-10-CM Official Coding and Reporting Guidelines April 1, 2020 through September 30, 2020, Chapter 1, Section g, Subsection 1.f. and 1.g.

How would pneumonia in a patient with COVID-19 be coded; J12.89, Other viral pneumonia, or J12.81, SARS-associated coronavirus pneumonia?

Effective for dates of service on or after April 1, 2020, pneumonia that has been confirmed as due to the 2019 novel coronavirus (COVID-19) should be coded using two diagnosis codes: U07.1, COVID-19, as the primary or first-listed diagnosis code, and J12.89, Other viral pneumonia, as an additional diagnosis code. For dates of service prior to April 1, 2020, a patient with pneumonia confirmed to be due to COVID-19 would be assigned diagnosis codes J12.89 as the primary or first-listed diagnosis code and B97.29, Other coronavirus as the cause of diseases classified elsewhere, according to the supplemental ICD-10-CM Official Coding Guidelines for coding encounters related to COVID-19 Coronavirus outbreak published by the Centers for Disease Control (CDC) on February 20, 2020.1 Additional guidance was developed jointly by the American Hospital Association (AHA) and the American Health Information Management Association (AHIMA) and published on March 20, 2020 with an update on March 24, 2020.2

1ICD-10-CM Official Coding Guidelines – Supplement Coding encounters related to COVID-19 Coronavirus Outbreak

2Frequently Asked Questions Regarding ICD-10-CM Coding for COVID-19 (March 24, 2020)

Would we use the B-code for other strains of coronavirus that the patient may test positive for with acute bronchitis?

Assign diagnosis codes J20.8, Acute bronchitis due to other specified organisms, and an appropriate secondary diagnosis code to identify the specific causative organism such as B97.21, SARS-associated coronavirus as the cause of diseases classified elsewhere, or B97.29, Other coronavirus as the cause of diseases classified elsewhere, for patients presenting with acute bronchitis due to a strain of coronavirus other than COVID-19. (3/25/2020)

If a patient came in with bronchitis and has been around sick people that are not documented as having COVID-19 and testing was done which came back negative, which codes would I use?

In the scenario outlined above, you would assign a code for the specific type of bronchitis that is documented in the record. No further codes are necessary, although you may assign diagnosis code Z20.9, Contact with and (suspected) exposure to unspecified communicable disease. (3/25/2020)

How would sepsis due to COVID-19 be coded after April 1, 2020?

The existing guidelines for coding viral sepsis have not changed. Viral sepsis was specifically addressed by the AHA in the 2016Q3 Coding Clinic. This guidance states, in part, that ICD-10-CM code A41.89, Other specified sepsis, should be assigned for a diagnosis of viral sepsis along with an additional diagnosis code to identify the specific type of viral infection. In the scenario outlined above, ICD-10-CM code U07.1, COVID-19, would be assigned. (3/25/2020)

If patient presented with aspiration pneumonia and was treated for three days, then was diagnosed with viral pneumonia due to COVID-19, should we code both pneumonias?

Yes, codes for both pneumonias would be assigned in the scenario described above since both conditions would meet criteria outlined in Section III (Reporting Additional Diagnoses) of the ICD-10-CM Official Guidelines for Coding and Reporting. Per these guidelines, additional diagnoses should be assigned for “all conditions that coexist at the time of admission, that develop subsequently, or that affect the treatment received and/or length of stay.” (3/25/2020)

If the doctor does not notate viral pneumonia with COVID-19, would you use J18.9?

If the physician documents viral pneumonia without any further clarification, ICD-10-CM code J12.9, Viral pneumonia, unspecified, should be assigned. It may be necessary to query the physician for further information as to the underlying cause of the pneumonia as there are many different viruses that may cause pneumonia. (3/25/2020)

How do you code presumptive positive COVID-19 infections?

Presumptive positive COVID-19 test results should be coded as confirmed, according to “Frequently Asked Questions Regarding ICD-10-CM Coding for COVID-19”, which was developed and published jointly by the AHA and AHIMA.1 Their guidance indicates that a presumptive positive result means that an individual has tested positive for the virus at a local or state level, but the test result has not yet been confirmed by the CDC.

1Frequently Asked Questions Regarding ICD-10-CM Coding for COVID-19 (March 24, 2020)

In the ER department, how do you code for presumed COVID-19 infection if no test is performed?

Patients presenting with signs and symptoms of COVID-19 where a definitive diagnosis has not been established should be assigned codes which reflect their signs and symptoms. If the physician documents suspected, possible, probable, or presumed COVID-19 infection, diagnosis code U07.1, COVID-19, should not be assigned. If the patient has a known or suspected exposure to COVID-19, you should add diagnosis code Z20.828, Contact with and (suspected) exposure to other viral communicable diseases. (3/25/2020)

Code Z03.818 can only be assigned as principal diagnosis code. How would you report possible exposure that was subsequently ruled out on an inpatient case since you are coding the condition or signs and symptoms that the patient has?

A code for possible or suspected exposure to the virus would only be necessary if the suspected exposure meets criteria for reporting of additional diagnoses, meaning that the exposure affected patient care in terms of requiring clinical evaluation, therapeutic treatment, diagnostic procedure, extended length of stay, or increased nursing care or monitoring. If the suspected exposure does meet criteria for reporting and the patient is without signs or symptoms of the disease, diagnosis code Z20.828, Contact with and (suspected) exposure to other viral communicable diseases, may be appropriate for reporting. According to the ICD-10-CM Official Guidelines for Coding and Reporting I.C.21.c.1, category Z20 indicates contact with, and suspected exposure to, communicable diseases and may be used for patients without signs or symptoms of a disease but who are suspected to have been exposed to it either by close personal contact with an infected individual or by virtue of being in an area where the disease is epidemic. If the patient has signs and symptoms of COVID-19, it would be appropriate to code the signs and symptoms that qualify for reporting of additional diagnoses. (3/25/2020)

Can we code for exposure for non-confirmed COVID-19 cases?

Although this scenario is not specifically addressed in the supplemental ICD-10-CM Official Coding Guidelines related to COVID-19 coronavirus outbreak, Vitalware would not recommend assigning a code for exposure unless there is exposure to a known COVID-19 patient. The intent of the supplemental coding guidelines is to allow for improved tracking of confirmed COVID-19 cases. Infections that are suspected or likely to be caused by the COVID-19 virus are not coded as confirmed cases and therefore unconfirmed exposure would also not be coded. (3/25/2020)

Should we assign a Z-code for suspected COVID-19 infection if we don’t have a confirmed diagnosis of COVID-19?


According to recently published ICD-10-CM Official Coding and Reporting Guidelines for April 1, 2020 through September 301, 2020 , Z20.828, Contact with and (suspected) exposure to other viral communicable diseases, should be assigned for patients who have had exposure to someone who is confirmed or suspected to have COVID-19, and the patient either tests negative or the test results are unknown. If the patient is suspected to have COVID-19 themselves without a confirmed diagnosis at the time of coding, diagnosis codes describing the patient’s signs and symptoms should be assigned. Only those patients who have a confirmed diagnosis of COVID-19 infection should be assigned a diagnosis code of U07.1, COVID-19, on or after April 1, 2020, or B97.29, Other coronavirus as the cause of diseases classified elsewhere, for dates of service prior to April 1, 2020. (3/31/2020)

1ICD-10-CM Official Coding and Reporting Guidelines April 1, 2020 through September 30, 2020

How do we code a patient with a suspected exposure that can’t be ruled out at the time of the visit?

According to recently published ICD-10-CM Official Coding and Reporting Guidelines for April 1, 2020 through September 30, 2020, Z20.828, Contact with and (suspected) exposure to other viral communicable diseases, should be assigned for patients who have had exposure to someone who is confirmed or suspected to have COVID-19, and the patient either tests negative or the test results are unknown. (3/31/2020)

What diagnosis code should be used to bill for COVID-19 testing when there is no order from the provider?

Per the ICD-10-CM Official Coding and Reporting Guidelines, asymptomatic patients who are being screened for COVID-19 and have no known exposure to the virus, may be assigned a diagnosis code of Z11.59, Encounter for screening for other viral diseases. These same guidelines also advise the assignment of diagnosis code Z20.828, Contact with and (suspected) exposure to other viral communicable diseases, for patients who have actual exposure to someone who is confirmed or suspected (not ruled out) to have COVID-19. If the lab test is subsequently found to be positive for COVID-19 infection, diagnosis code U07.1, COVID-19, should be assigned, even if the patient was asymptomatic. (05/05/2020)

Do you have any advice for coding the COVID-19 lab tests in circumstances where the patient has been discharged before test results are available, and the physician doesn’t mention why the test was ordered?

The ICD-10-CM Official Coding Guidelines state that signs/symptoms associated with COVID-19 should be assigned when a definitive diagnosis has not been established. The guidelines further state that code Z20.828, Contact with and (suspected) exposure to other viral communicable diseases, should be assigned as an additional code for patients who have either an actual or a suspected contact with or exposure to someone who has COVID-19. If the lab test is subsequently found to be positive for COVID-19 infection, diagnosis code U07.1, COVID-19, should be assigned, even if the patient was asymptomatic. (05/06/2020)

What ICD-10-CM code would you use for pre-admission COVID-19 testing? Does this differ if the test is done on the same day as the service/procedure or prior to the procedure? Should this be reported on the same claim?

For dates of service from April 1 through September 20, 2020, ICD-10-CM diagnosis code Z11.59, Encounter for screening for other viral diseases, would be assigned when screening asymptomatic patients with no known exposure to the virus; diagnosis code Z20.828, Contact with and (suspected) exposure to other viral communicable diseases, would be assigned when patients with a known or suspected exposure to the disease are being screened.

For dates of service on or after October 1, 2020, there are updated guidelines that differ from current guidelines. Additionally, the guidelines during the COVID-19 pandemic differ from those for post-pandemic reporting. During the pandemic, encounters for COVID-19 testing in asymptomatic patients, which includes preoperative testing, should be assigned diagnosis code Z20.828, Contact with and (suspected) exposure to other viral communicable diseases.

Post-pandemic, the guidelines state that patients receiving preoperative evaluations only would have a code from category Z01.81 sequenced first, with an exception when the encounter is for chemotherapy or radiation therapy. Guidelines regarding the coding of signs & symptoms and exposure to COVID-19 remain the same. [1] Coding guidance will be updated as changes in the pandemic status changes.[2]

CMS stated that pre-admission testing would be covered within the “normal” Outpatient Prospective Payment System (OPPS) or Inpatient Prospective Payment System (IPPS) guidelines in place, meaning within the 1-day or 3-day payment window.[3] The appropriate CPT®/HCPCS codes would be used to report the laboratory tests. The International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) diagnosis codes should be reported. (08/27/2020)

When a patient has recovered from COVID-19 infection but has residual effects and requires aftercare therapies, how would we indicate that COVID-19 was the cause but is not a current infection?

There currently is no specific International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) code specifically for the sequela of COVID-19. Current guidance states that

diagnosis code B94.8, Sequelae of other specified infectious and parasitic diseases, should be assigned as a secondary diagnosis code.[1] (10/08/2020)

A patient comes in symptomatic for COVID-19 with no stated exposure, and the provider diagnoses an upper respiratory infection (URI) and orders a screening test for COVID. The patient does get tested for COVID and the results are documented as negative. In this scenario we DO NOT code Z20.828. Is that correct?

The current Fiscal Year (FY) 2021 ICD-10-CM Coding Guideline ‘Signs and symptoms without definitive diagnosis of COVID-19’ states that the signs and symptoms may be used as the first-listed diagnosis code. Further, the Guidelines state, “If a patient with signs/symptoms associated with COVID-19 also has an actual or suspected contact with or exposure to COVID-19, assign Z20.828, Contact with and (suspected) exposure to other viral communicable diseases, as an additional code.[1] (10/08/2020)

If the patient is asymptomatic with no known exposure, what ICD-10-CM code would you use? Why is the screening code Z11.52, Encounter for screening for COVID-19, not used?

Current coding guidance states that ICD-10-CM code Z20.822, Contact with and (suspected) exposure to COVID-19, should be reported. During a wide-spread pandemic, it is to be assumed that everyone has had exposure to the virus.[1] After the pandemic is ended, then the expectation is that coding guidance will change.

Previous coding guidance published in the Coding Clinic® for ICD-10Second Quarter 2020 has been superseded with this more current guidance, as published in the Coding Clinic® for ICD-10, Third Quarter 2020. ICD-10-CM code Z03.818, Encounter for observation for suspected exposure to other biological agents ruled out, would not be used at this time.[2] (02/04/2021)

[2] AHA Coding Clinic® for ICD-10, Third Quarter 2020, “Frequently Asked Questions Regarding ICD-10-CM Coding for COVID-19”, (August 5, 2020)

Is there any ICD-10-CM code for “status post COVID-19 vaccination”?

No, there is no specific ICD-10-CM code specific to a patient who is post-COVID-19 vaccination. As codes and coding guidelines evolve, a diagnosis may become available. (02/04/2021)

How do we code for a long-hauler with a negative COVID-19 test. Do we code it as history?

Current ICD-10-CM Coding Guidelines state that codes to describe the presenting signs and symptoms would be coded as first-listed diagnoses followed by Z86.16, Personal history of COVID-19, after the COVID-19 infection has resolved, and the test results are negative.[1] (02/04/2021)

If a patient currently has a positive COVID-19 test, plus past history, should we code for both?

For your scenario, you would assign ICD-10-CM code U07.1, COVID-19, and not report the personal history. The current guidelines state in guideline I.C.21.c.4, “Personal history codes explain a patient’s past medical condition that no longer exists and is not receiving any treatment, but that has the potential for recurrence, and therefore may require continued monitoring.” Because the patient is currently receiving treatment for COVID-19, the additional code for personal history would not be needed. [1] (02/04/2021)

How do we code the results if it states “indeterminate?” Would that be coded as a positive result?

Only confirmed cases of COVID-19, as documented by the provider or through a positive test result, are to be coded. If the provider documents “suspected,” “possible,” “probable,” or “inconclusive” COVID-19, do not assign code U07.1. Note that confirmation does not require documentation of a positive test result; the provider’s documentation is sufficient. Instead, code the signs and symptoms reported, along with ICD-10-CM code Z20.822, Contact with and (suspected) exposure to COVID-19[1] (02/04/2021)

If a patient has infective myocarditis due to COVID-19, should you add ICD-10-CM code B97, Viral agents as the cause of diseases classified elsewhere, or would you report ICD-10-CM codes U07.1, COVID-19, and I40.0, Infective myocarditis?

If the initial COVID-19 infection has resolved, you would assign ICD-10-CM code I40.0, Infective myocarditis, as the principal diagnosis and B94.8, Sequelae of other specified infectious and parasitic diseases, as a secondary diagnosis. If the patient is still being treated for COVID-19, then you would report a principal diagnosis code of U07.1, COVID-19, with an additional diagnosis code of I40.0, Infective myocarditis[1] (02/04/2021)

[1] AHA Coding Clinic® for ICD-10, Third Quarter 2020, “Frequently Asked Questions Regarding ICD-10-CM Coding for COVID-19”, (August 5, 2020)

Is there a special code for adverse effects of COVID-19 vaccination?:

There is no specific ICD-10-CM code for adverse effects of COVID-19 vaccination. When coding an adverse effect of a COVID-19 vaccination that has been correctly prescribed and properly administered, you should assign code(s) to describe the specific adverse reaction followed by ICD-10-CM code T50.B95, Adverse effect of other viral vaccines. [1] (02/04/2021)

Coding for COVID-19 Lab Testing and Specimen Collection

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