Like many things in life, the answer depends on the situation.
Pensions and Social Security payments are not considered as earned income for most parts of the US 1040 Tax Form, but are considered as earned income for some lending institutions.
Pensions and Social Security benefits are included as income in determining support for dependants and filing status.
Pensions and Social Security benefits are not entirely taxable, but the parts that are are taxed at the same rate(s) as your earned income.
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