New York City's health department counts deaths from "laboratory-confirmed" COVID-19 separately from other "probable" cases. Probable cases include deaths where symptoms and medical history indicate COVID-19 was likely, but there is as of yet no test result. In the early days of the outbreak a shortage of reliable tests and overtaxed personnel and facilities limited testing.
The New York methodology is consistent with advice from the Centers for Disease Control, which calls for using "best clinical judgment" to determine if COVID-19 was likely.
Statistics and death counts continue to change as doctors, scientists and public health officials learn more about the coronavirus.