What was the annual US inflation rate each year from 2017 to 2020?

1. Conflicting claims boiled down: which years moved and by how much?

The primary claim under review lists 2017 = 2.1%, 2018 = 2.4%, 2019 = 1.8%, 2020 = 1.2%, a sequence repeated across several supplied analyses and historical tables ^{[8] [5] [7]}. A secondary analysis reports the same numbers except for 2019 = 2.3%, introducing a notable discrepancy ^[6]. This disagreement matters because a difference of 0.5 percentage point for a single year can influence short-run trend interpretation. The majority of the supplied sources—especially those referencing historical inflation tables—support the 1.8% 2019 figure, so the weight of the provided evidence favors the lower 2019 rate ^{[5] [7]}.

2. Why one source reports a higher 2019 rate: methodology and index choices

One supplied analysis that lists 2019 at 2.3% cites Consumer Price Index data but does not clarify whether the figure is an annual average, month-to-month measure, or a year-over-year percentage taken from a specific month ^[6]. Different CPI computations—annual average CPI change, December-to-December change, or seasonally adjusted figures—can produce different headline numbers. The other sources present annual historical series that align on the 1.8% number, indicating they used the commonly reported annual average CPI-U percent change metric ^{[5] [7]}. Absent explicit methodology in the divergent analysis, the discrepancy appears attributable to different aggregation choices rather than contradictory underlying data ^{[6] [7]}.

3. Cross-checks and source weight: which datasets carry more authority here?

The supplied materials include historical tables and CPI compilations presented as broad historical series; those consistently show the 2.1 / 2.4 / 1.8 / 1.2 sequence ^{[8] [5] [7]}. The lone outlier comes from a dataset labeled Consumer Price Index data that lists 2019 at 2.3%, but the same group also supplies alternative analyses agreeing with the 1.8% figure, highlighting internal inconsistency ^{[6] [9]}. Given this pattern, the most authoritative synthesis within the provided data supports the 1.8% 2019 figure, because multiple independent tables in the dataset converge there ^{[5] [7]}, while the 2.3% observation stands alone and lacks methodological clarity ^[6].

4. Big-picture implications: trend interpretation across 2017–2020

Viewed as a sequence—2.1% ^[1], 2.4% ^[2], 1.8% ^[3], 1.2% ^[4]—the supplied data depict an economy that peaked near 2.4% in 2018 and then cooled through 2020, ending with historically low inflation in the pandemic year of 2020. The alternate 2.3% 2019 reading would flatten that decline and suggest more persistent inflation into 2019, altering short-term narrative and any policy inferences. Because most supplied sources support the steeper decline by 2019, the dominant interpretation in the provided material is of disinflation entering 2019 and a further dip in 2020 ^{[8] [5] [7]}.

5. Final assessment and guidance for readers wanting to verify

Based on the collection of supplied analyses, the best-supported answer is 2017: 2.1%, 2018: 2.4%, 2019: 1.8%, 2020: 1.2%; the lone divergent 2019 figure (2.3%) likely reflects a different CPI calculation or reporting choice and should be treated as an alternate-method estimate unless its methodology is clarified ^{[5] [6] [7]}. Readers seeking confirmation should consult the underlying CPI annual-average series used by the historical tables in these materials to reconcile aggregation differences; the supplied historical-series sources converge on the 1.8% 2019 number and therefore carry the most consistent weight within the provided evidence ^{[8] [5] [7]}.