There's an interesting geographical trend developing in the U.S. retirement market, as the gap widens between the best states to retire on a fixed income and the worst states to do the same.

We'll get to those "best states" in a moment, but the reasons why the retirement-by-state gap exists in the first place are important ones, like the cost of living, the tax impact, and the prospects of owning a home or renting one.

Which U.S. states rule the roost when it comes to the best places to retire on a fixed income?

The fact is, those key issues listed above frame the narrative, and explain why states like Alabama are a great place to retire, income-wise, and why high-tax, high-cost of living states like California and New York are at the bottom of the list.

These states represent the best deal, financially, when you're planning to retire: