The median income of Polk County residents was an inflation-adjusted $30,895 per year. Polk County had 2,038 households in 2017, with a population of 5,244.
The county with the highest median resident income in the state was Sarpy County. Sarpy County's median income was $36,763 per year after adjusting for inflation – $5,868 more than Polk County. It had 63,851 households in 2017 and a population of 175,188.
Grant County had the lowest annual resident income among counties in Nebraska, with a median income of only $20,682 per year. That was $10,213 less than the median income in Polk County at the time. Grant County had 274 households in 2017 and a population of 682.
The table below shows the state's counties ranked by median annual resident earnings in 2017.