Effective April 1, 2020 through September 30, 2020, a new diagnosis code U07.1 was added to the ICD-10-CM code set for the novel coronavirus COVID-19: U07.1. The ICD-10-CM Official Coding and Reporting Guidelines– Chapter 1 (Certain Infections and Parasitic Disease) was updated with guidance on the appropriate assignment of the new COVID-19 diagnosis code.^[1] In addition, the MS-DRG grouper was also updated to accommodate the new COVID-19 diagnosis code. Below is a summary of the key coding principles and guidance for assignment of the new COVID-19 diagnosis code U07.1.

1. The new COVID-19 diagnosis code U07.1 is effective April 1, 2020 and is only applicable for dates of service and dates of discharge on or after April 1, 2020.^[2]

For hospital inpatient admissions, if the patient’s date of discharge is on or after April 1, 2020, the new COVID-19 diagnosis code may be used if all the coding requirements are met. This means that for patients admitted prior to April 1, 2020, who are subsequently discharged on or after April 1, 2020, the new COVID-19 diagnosis code may be used. For outpatient settings, such as an Emergency Department visit or a physician office, the new COVID-19 diagnosis code is only applicable to dates of service on or after April 1, 2020.

2. The new COVID-19 diagnosis code U07.1 can only be applied to confirmed COVID-19 cases pursuant to the ICD-10-CM Official Coding and Reporting Guidelines Effective April 1, 2020 through September 30, 2020.

The new COVID-19 diagnosis code can only be used with confirmed cases of COVID-19. The code may be applied to cases that have documentation of the following:

- Documentation of a positive COVID-19 test result (confirmed by CDC)

- Documentation of a presumptive positive test result. A “presumptive” positive test means a positive COVID-19 test result at the local or state level that has not been confirmed by CDC. This applies to both inpatient and outpatient settings.^[3]

- Documentation of the COVID-19 diagnosis by the provider. The documentation by a provider of a COVID-19 diagnosis is sufficient documentation to code as a confirmed case of COVID-19. This is an exception to the hospital inpatient coding guidelines in that the physician documentation does not require documentation of the type of test performed by the physician to confirm the COVID-19 diagnosis. This is an exception for acute inpatient cases only.^[4]

- Documentation of probable, suspected, possible, COVID-19 cases does not meet the criteria to code U07.1 for confirmed COVID-19. Instead, the symptoms presented by the patient should be coded, such as cough (R06) or shortness of breath (R06.02). If the documentation is inconclusive, then the symptoms or encounter reason, such as suspected exposure to COVID-19, should be coded. If a COVID-19 test result is pending at the time of discharge, the hospital may hold a chart for coding for the COVID-19 test result. The American Hospital Association (AHA) and American Heatlh Information Management Association (AHIMA), recommend facility-specific guidelines for holding claims for submission to payers until after tests results are received.^[5]

- Asymptomatic patient with confirmed COVID-19 diagnosis should be coded with U07.1. For an asymptomatic patient, this means either a positive COVID-19 test result or a presumptive positive COVID-19 test result is needed to assign the COVID-19 diagnosis code.

3. The new COVID-19 diagnosis code U07.1 is not automatically the primary diagnosis code.

The new COVID-19 diagnosis code must still meet the definition of the primary diagnosis code (PDX) pursuant to the Uniform Hospital Discharge Data Set (UHDDS) in order to be assigned as the PDX.^[6] For example, the rule requiring codes from Chapter 15 (Pregnancy, Childbirth, and the Puerperium) to be coded as PDX still applies even with a confirmed COVID-19 diagnosis. Similarly, when a patient has confirmed COVID-19 diagnosis and sepsis, the guidelines for application of the PDX in the sepsis guidelines still apply.

With a confirmed COVID-19 diagnosis, the other conditions and manifestations are subsequently coded. For example, if a patient has pneumonia that is confirmed due to the COVID-19 coronavirus, then COVID-19 (U07.1) is the PDX and Other Viral Pneumonia (J12.89) is the secondary diagnosis. The sequencing of the diagnosis codes for all inpatient cases is critical to the MS-DRG assignments, including whether there is an MCC or CC assignment. This is also true with respect to the new COVID-19 diagnosis code as discussed in more below.

4. Effective April 1, 2020, the MS-DRG Grouper Was Updated to Include Edits for the new COVID-19 diagnosis code U07.1.

The MS-DRG Grouper software version 37.1 R1 is the version updated to accommodate the new COVID-19 diagnosis code U07.1 as an MCC and uses edits to validate claims.^[7] Effective for dates of discharge on or after April 1, 2020, the new diagnosis code U07.1 for COVID-19 is identified as a Major Complication Comorbidity (MCC) and grouping will be dependent on the Major Diagnostic Category (MDC). There are specified MDC and corresponding MS-DRGs for neonates and patients with HIV infections, which will accommodate the new COVID-19 diagnosis code. For remaining patients, the Respiratory Infections MCD will accommodate the new COVID-19 diagnosis code. The COVID-19 diagnosis code will be an MCC only if coded at the PDX. If COVID-19 is not the PDX, then it will only exclude itself from acting as an MCC under the CC exclusions list.

While the PDX sequencing and coding of all diagnosis are important, the appropriate coding of ICD-10-PCS codes for procedures performed, such as mechanical ventilation or dialysis, is also important to ensure accuracy and proper MS-DRG assignments. Below is a chart summarizing the MDC and corresponding MS-DRGs that will accommodate the new COVID-19 diagnosis code.

[1] Excerpt of the ICD-10-CM Official Coding and Reporting Guidelines effective April 1, 2020, that is related to COVID-19 diagnosis code U071.9 can be found at: https://www.cdc.gov/nchs/data/icd/COVID-19-guidelines-final.pdf. The ICD-10-CM Official Coding and Reporting Guidelines are updated yearly effective October 1 to address the updated ICD-10 code set effective on that date. The next update will be on October 1, 2020, which is why this update for COVID-19 is effective April 1, 2020 through September 30, 2020.

[2] For services with dates of service or dates of discharge prior to April 1, 2020, the CDC interim coding advice may be found at https://www.cdc.gov/nchs/data/icd/interim-coding-advice-coronavirus-March-2020-final.pdf.

[3] ICD-10-CM Official Coding and Reporting Guidelines, Chapter 1, Section I.C.1.g.1.a.

[4] Id.

[5] See https://journal.ahima.org/ahima-and-aha-faq-on-icd-10-cm-coding-for-covid-19/.

[6] This rule applies to all non-outpatient settings (e.g. acute care hospitals, home health, nursing homes, etc.).

[7] See CMS MS-DRG Grouper Version 37.1 R1 update at https://edit.cms.gov/files/document/icd-10-ms-drgs-version-371-r1-effective-april-1-2020-updated-march-23-2020.pdf.