Officially, the CDC shows 335K excess deaths in 2020. But, something is very wrong with their baseline expected deaths. For some reason, they "expected" mortality to decline this year - after steadily increasing annually for the past decade:

If the CDC had simply extended their average expected deaths trend into 2020, excess deaths would be reduced by 114K. In other words, about 1/3 of CDC reported excess mortality is due entirely to an artificially low baseline:

To paint this in the best possible light, I believe the CDC may have reduced expected 2020 deaths because of the extraordinarily mild Winter deaths observed in 2019. However, past trends indicate that low mortality years tend to be followed by high mortality years.

This is a well-documented phenomenon known as "mortality displacement". Given the low number of deaths observed in 2019, the CDC should have expected more deaths year, not fewer. Accounting for mortality displacement, "true" excess mortality this year is around 155K:

Looking by week, it is clear that the majority of the gap between a reasonable forecast and that reported by the CDC lands at the beginning of 2020. The CDC seems to have "expected" the complete lack of a flu season in early 2020...