Just as SARS-CoV-2 is evolving through genomic mutations, codes and coding instructions for COVID-19 are continually changing too. In another unprecedented mid-year ICD-10 classification update, new COVID-19-related codes became effective Jan. 1, 2021.
When COVID-19 meets the definition of principal diagnosis, code U07.1 is assigned first, followed by the appropriate codes for the associated manifestations, such as those in Table 1. The new codes related to COVID-19 for 2021 are listed in Table 2.
Only confirmed cases of COVID-19, defined as a positive test result or clinician documentation that the individual has COVID-19, are assigned code U07.1 and considered a confirmed case. A positive test result or documentation of the test result in the record is not required if a clinician has definitively documented a diagnosis of COVID-19. (Note that tests for SARS-CoV-2, both standard polymerase chain reaction and rapid antigen, are highly accurate when positive but are frequently falsely negative. In other words, a negative test does not rule out COVID-19.)
In patients with a respiratory manifestation of COVID-19, clinicians do not have to link the two in documentation, since the causal relationship is implied. Pulmonary embolism is not one of the COVID-19-related “pulmonary manifestations” but rather a vascular condition resulting from the virus's thromboembolic tendency.
When the reason for the admission is a nonrespiratory manifestation of COVID-19, COVID-19 is again the principal diagnosis and any manifestations are secondary. In applying this rule, the clinician must specifically link COVID-19 and the nonrespiratory manifestation (for example, “DVT due to or resulting from COVID-19”). Common nonrespiratory manifestations include thromboembolism resulting in stroke, myocardial infarction, or pulmonary embolism; multisystem inflammatory syndrome in children; cytokine release syndrome; Guillain-Barré syndrome; and COVID-related enteritis.
In cases where the patient has a condition with contrary sequencing instructions, such as sepsis, childbirth, or complications of transplant, follow that condition's sequencing instructions. For example:
- Admitted with COVID-19 pneumonia causing sepsis. Assign A41.89 (viral sepsis) as principal diagnosis with U07.1 (COVID-19) and J12.89 (pneumonia due to COVID-19) as secondary diagnoses.
- Status post-lung transplant admitted for management of respiratory manifestations of COVID-19. Assign transplant complication code (category T86) as principal diagnosis if the complication affects the function of the transplanted organ. Assign code T86.812 as principal diagnosis and U07.1 and the respiratory manifestation as secondary diagnoses.
- Admitted for COVID-19 during pregnancy or the peripartum period. Assign code O98.5 (other viral diseases complicating pregnancy, childbirth, and the puerperium) as principal diagnosis and code U07.1 with the associated manifestation(s) as secondary diagnoses.
When a patient is admitted for COVID-19 and an unrelated condition, sequencing depends on the OCG Section II.C instructions for principal diagnosis: “When two or more diagnoses equally meet the criteria for principal diagnosis as determined by the circumstances of admission, diagnostic workup, and/or therapy provided....any one of the diagnoses may be sequenced first.”
The assignment of correct codes for COVID-19 depends on the distinction between a current, active infection or one that has resolved. To help differentiate, the CDC says, “Available data indicate that persons with mild to moderate COVID-19 remain infectious no longer than 10 days after symptom onset. Persons with more severe to critical illness or severe immunocompromise likely remain infectious no longer than 20 days after symptom onset.” Clinicians should therefore consider these time frames for resolution of COVID-19. The CDC strongly advises not repeating testing following an initially positive test in asymptomatic individuals but notes that a repeat test may be useful in symptomatic persons.
When a patient is admitted with a sequela of a resolved COVID-19 infection, sequence the sequela manifestation as principal diagnosis with a secondary diagnosis code of B94.8 (sequelae of other specified infectious and parasitic diseases). Some common sequelae include pneumonia, pneumothorax, cytokine release syndrome, thromboembolism resulting in stroke, myocardial infarction, deep venous thrombosis, pulmonary embolism, and heart failure (for those who had COVID-19 myocarditis).
As an example, consider the patient admitted for a pulmonary embolism following an admission 28 days earlier for COVID-19 pneumonia. The patient no longer has COVID-19. Assign pulmonary embolism as principal diagnosis and B94.8 as secondary diagnosis. Do not assign U07.1 or Z86.16 (personal history of COVID-19).
When patients are admitted for a condition that appears unrelated to previously having had COVID-19, assign the unrelated condition as principal diagnosis and assign code Z86.16 (personal history of COVID-19) as a secondary diagnosis. Personal history codes explain patients' past medical conditions that are no longer being treated but may have potential for recurrence.
For example, if an elderly patient is admitted for hip fracture with a prior admission one month earlier for COVID-19 that has resolved, assign hip fracture (M84.459A) as principal diagnosis and code Z86.19 (personal history of COVID-19) as a secondary diagnosis.
Ask Dr. Pinson
Q: I've gotten some questions around billing for procedures that are not successful, for example, a lumbar puncture that was attempted but not successful. Do you suggest modifying this with modifier 52?
A: Use modifier 52 if a procedure is unsuccessful, that is, if a clinician plans or expects a reduction in the service or if the clinician electively cancels the procedure prior to completion. Put another way, modifier 52 applies when a reduction in service occurs by choice (either the clinician's or the patient's). Unsuccessful means the clinician electively decided to terminate the procedure prior to completion. Modifier 53 is used when a clinician discontinues a procedure due to risk to the patient, equipment failure, or other extenuating circumstances.
Q: If a patient has severe mitral valve regurgitation due to torn/ruptured chordae tendineae and has to have chords replaced and annuloplasty, can we code both the regurgitation and torn chords? If so, which would you consider the primary diagnosis?
A: Rupture of mitral chordae tendineae (code I51.1 or I23.4 depending on the cause, spontaneous or due to myocardial infarction, respectively) disconnects the link between the mitral valve and the left ventricle, causing mitral valve regurgitation (I34.0). ICD-10-CM does not prohibit assignment of both codes for the same encounter.
Clinically speaking, the mitral regurgitation is the direct result of the ruptured chordae. According to the ICD-10-CM Official Guidelines for Coding and Reporting, when two interrelated conditions potentially meet the definition of principal diagnosis, either condition may be sequenced first unless the circumstances of admission, the therapy provided, the Tabular List, or the Alphabetic Index indicate otherwise.
Q: To document severe malnutrition, can one select malnutrition parameters from the American Society for Parenteral and Enteral Nutrition (ASPEN) across the clinical contexts, for example, consuming less than 75% of energy requirement for more than a month from the chronic context and moderate muscle and fat loss from the acute context?
A: One must stay within the specific clinical context one is using (acute, chronic, socioenvironmental), not pick criteria from different contexts. There's also a problem with using the caloric intake for severe malnutrition in the chronic context you mentioned: It's the same as nonsevere and out of sync with the acute and socioenvironmental contexts where the cutoff is less than 50%. I advise using less than 50% in all three for consistency and compliance concerns.