@pelz86 Inflation was lower in 2023 than it was in 2022, so the increase for 2024 is a bit less than it was for 2023.
It's not arbitrary. It's based on a formula specified in the law, which involves figuring out the total inflation since some "base" year (which I think is like 2005 or 2008) and multiplying that inflation figure by the base contribution amount from that year, then rounding down to the nearest multiple of $500. So it's possible that the "pre rounded" amount could have been higher, even up to $23,499, but would only end up as $23,000 for the year after rounding. The rounding doesn't impact future years since the calculation is always done from scratch for each year relative to the original base year in the distant past, not from one year to the next. So, over time it does accurately track inflation, even if some years are closer than others due to the rounding.