Which states experienced the largest year‑over‑year percent increase in all‑cause mortality in 2020, by exact ranking and percentages?

1. Pandemic shock at the national level — the baseline numbers that anchor every state comparison

Federal reporting shows the scale: total U.S. deaths increased by about 19% from 2019 to 2020, a jump the Census calls the largest in a century and far above the pre‑pandemic annual average increase of ~1.6% from 2010–2019 ^[1], while the CDC’s provisional mortality releases report a 15.9% rise in the age‑adjusted death rate in 2020, underscoring how abnormal 2020 was compared with prior trends ^[2].

2. Which states the major analyses flag as hardest hit (ranking without precise percentages in these sources)

The Census Bureau’s excess‑mortality modeling and reporting explicitly point to Mississippi, Louisiana, New York, New Jersey and Washington, D.C. as among the areas with the highest excess mortality during the pandemic’s first year—particularly during the long October 2020–March 2021 wave—while noting “substantial variation by state” across the country ^[3]. The Census story and related Demography work therefore functionally rank those jurisdictions at the top of the list of worst relative increases, but the Census presentation in the excerpts does not provide a single, simple state‑by‑state percent‑increase table suitable for verbatim ranking with exact decimals in the material supplied here ^{[3] [1]}.

3. Why an authoritative, state‑by‑state percent ranking isn’t extractable from the supplied material

The sources provided include national totals and assessments of which states experienced the most excess deaths (Census, NCHS) and point to state‑level mortality tables maintained by federal portals (NVSS, HDPulse), but none of the supplied snippets include a complete, state‑by‑state list of year‑over‑year percent increases in all‑cause mortality for 2020 with exact percentages and a definitive rank order that can be cited directly ^{[4] [5] [6] [3]}. Attempts to assemble such a ranked list therefore require consulting state‑level mortality tables from NVSS/HDPulse or KFF’s state indicators and computing percent changes using 2019 and 2020 totals—actions the current materials recommend but do not themselves present ^{[4] [7] [5]}.

4. How different data choices and timing change the apparent ranking

Comparisons can vary depending on whether analysts use raw counts, crude rates, age‑adjusted rates, or excess‑death models; the CDC’s provisional age‑adjusted rise (15.9%) differs from total‑death percent growth (≈19%) because age structure and reporting lags matter ^{[2] [1]}. Our World in Data and method papers also caution that timeliness and state variability in death registration can distort early rankings until death certificates are finalized, meaning preliminary state percentages may be revised upward over months ^[8].

5. What a rigorous answer requires and recommended next steps for a definitive ranked list

To produce an exact, fully‑sourced ranking of states by year‑over‑year percent increase in all‑cause mortality for 2020—with precise percentages—one must extract 2019 and 2020 death totals or rates from NCHS/NVSS state mortality tables (or equivalent HDPulse/KFF datasets), compute percent changes (or use NCHS‑provided state percent changes), and cite those tables directly; the supplied sources point to those repositories but do not themselves contain the finished ranked table ^{[4] [5] [7]}. Until those state‑level numbers are pulled from NVSS/HDPulse and cited, asserting a numeric rank with exact percentages would exceed what the provided reporting supports.