As a federal employee you will normally have at least these sources of income:
Your Pension
TSP (Thrift Savings Plan)
Social Security
And most of the time, all three of these will be taxed on the federal level (at least to some degree) but if they are taxed on the state level will depend on where you live and what income source it is.
These lists break it down.
States That Won’t Tax Your Social Security Income
Alaska
Florida
Nevada
New Hampshire
South Dakota
Tennessee
Texas
Washington
Wyoming
States That Won’t Tax Your Pension Income
Alaska
Florida
Nevada
South Dakota
Tennessee
Texas
Washington
Wyoming
New Hampshire
Alabama
Illinois
Hawaii
Mississippi
Pennsylvania
(Some states, such as New York, don’t tax federal pensions but do tax some private pensions.)
States That Won’t Tax Your TSP Income
Alaska
Florida
Nevada
New Hampshire
South Dakota
Tennessee
Texas
Washington
Wyoming
Illinois
Mississippi
Pennsylvania
States That Don’t Have State Income Taxes
Alaska
Florida
Nevada
New Hampshire (earned wages only)
South Dakota
Tennessee
Texas
Washington
Wyoming
States That Don’t Have Sales Tax
Alaska
Delaware
Montana
New Hampshire
Oregon