I don't know about other states, but in CA a death certificate has 3 blanks under cause of death: Blank due to blank due to blank. Then a box to list contributing factors. So for influenza it might read "respiratory failure due to bacterial pneumonia due to influenza. Diabetes mellitus, hypertension, coronary artery disease." For Covid-19 it might read "respiratory failure due to viral pneumonia due to COVID-19. Diabetes, hypertension, coronary artery disease."
There's no standardization. Some docs write "cardiac arrest" in the first box, which is dumb unless it was a sudden, unexpected arrest, since cardiac arrest is how everyone dies from any disease. Someone might write COVID-19 in the first box. Someone else might write "COVID-19 due to SARS-CV2" which seems unnecessarily pedantic to me. As long as COVID-19 or coronavirus or SARS-CV2 is somewhere in the 3 boxes it should be considered the cause of death for statistical purposes. That is, the person wouldn't have died if it weren't for the virus. OTOH if the death certificate read "acute metabolic failure due to lysol ingestion due to stupidity. Contributing factors COVID-19" Covid-19 should not be considered the cause of death. Remember that the death certificate is filled out by a doctor who considers doing it a waste of time (death certificates often bounce around a hospital or clinic looking for someone willing to fill them out) and read and entered into a database by a county clerk.
The death certificate has nothing to do with billing. That is done by the diagnoses listed and documented in the medical record. I don't know if COVID-19 is a valid diagnosis for billing purposes or if it is billed as viral pneumonia or respiratory failure or whatever other complication of it the patient died of. For medicare purposes and probably for private insurance any diagnosis that is billed has be documented by certain criteria. Just listing diagnosis is not enough. Billing for an undocumented diagnosis might be considered Medicare or insurance fraud so doctors and billers will usually be careful not to enter a diagnosis without documentation.
Interesting article about proning (placing a patient on their stomach) to avoid intubation.
https://onlinelibrary.wiley.com/doi/...111/acem.13994