Median household income by state: the gap grew in dollars, not in proportion

Key takeaways

The gap between the highest and lowest jurisdiction grew from $35,254 in 2015 to $54,007 in 2023, up 53 percent in dollars. As a ratio it barely moved: the top has stayed close to twice the bottom the whole window.
The median state's median household income rose 36.4 percent, $54,736 to $74,632. Consumer prices rose about 29 percent over the same years, so the typical state gained roughly 6 percent in real terms.
Only the District of Columbia has crossed $100,000 ($108,210 in 2023). Massachusetts ($99,858) and New Jersey ($99,781) sit just under the line.

What's happening

The chart compresses 51 income figures per year into one box: the box spans the middle half of the states, the line inside it is the median state, and the whiskers reach the highest and lowest. Read left to right, the whole shape climbs and stretches. Every part of the distribution ends higher than it started, and the 2023 box sits entirely above the 2015 one; even 2023's poorest state, Mississippi at $54,203, would have landed near the middle of the 2015 pack.

That is the double story boxplots are built to tell. A single line for "US median income" would show the climb; the boxes show who the climb included, and by how much.

2 to 1

The rough ratio between the highest and lowest jurisdiction in every year of the window: 1.87 in 2015, 2.00 in 2023. The dollar gap grew 53 percent; the proportions held.

A gap that grows in dollars and holds in proportion

Two things are true at once. In dollars, the spread widened every step of the way: $35,254 separated top from bottom in 2015, $54,007 in 2023. In proportion, nothing changed: the top jurisdiction has earned about twice the bottom for the entire window. When every state's income compounds at a similar rate, the dollar distances stretch even though nobody's relative position moves much. The boxes make that visible: the middle half of states (the box itself) spanned $13,733 in 2015 and $16,529 in 2023, growth of 20 percent, slower than the extremes.

The inflation footnote matters here. These are current-dollar figures, and consumer prices rose about 29 percent across the window, so the median state's 36.4 percent gain is roughly 6 percent in purchasing power. Eight years of climbing boxes compress, in real terms, to a modest step up.

Who moved inside the boxes

The states that climbed the distribution are the same corridor that led the rent story: Idaho grew fastest at 55.2 percent ($48,275 to $74,942), then Arizona at 50.1 and Utah at 48.5. The slowest were the energy states and Alaska: North Dakota at 26.4 percent, Wyoming at 20.3, Alaska at 18.1. Six states in all grew more slowly than prices did (those three plus Louisiana, Oklahoma, and Connecticut), which means their medians fell in real terms. At the top, the District of Columbia became the first jurisdiction past $100,000 in 2022 and reached $108,210 in 2023.

What to watch

Whether Massachusetts or New Jersey becomes the first state past $100,000 in the next ACS release; both closed 2023 within $250 of the line. Whether the top-to-bottom ratio finally breaks above two and stays there, which would mark proportional divergence rather than shared growth. And the pairing with rent by state, since the states with the fastest income growth are also the ones where rent climbed hardest.

Common questions

Which state has the highest median household income?

Massachusetts, at $99,858 in 2023, with New Jersey at $99,781. The District of Columbia sits above every state at $108,210.

Which state has the lowest?

Mississippi, at $54,203 in 2023. It held the bottom position in every year of the window except 2017 and 2018, when West Virginia was lowest.

Is the income gap between states growing?

In dollars, yes: the top-to-bottom spread grew 53 percent from 2015 to 2023. In proportion, no: the highest jurisdiction has earned about twice the lowest throughout.

Are these figures adjusted for inflation?

No, each year is in its own dollars. Prices rose about 29 percent over the window, so the median state's 36.4 percent nominal gain is roughly 6 percent real.

Data: median household income by state (US Census Bureau, American Community Survey one-year estimates, 2015 to 2023, all 50 states and DC, current dollars), from the Kitegraph library. Each box is a Tukey summary of the 51 values for that year; the ACS published no one-year estimates for 2020. The inflation comparison uses BLS CPI-U annual averages (2015 to 2023, up 28.6 percent).