Colorado law excludes from Colorado state income tax total pension
income up to $20,000 per year per person for those retirees age 55
through 64, or $24,000 for those retirees age 65 and over. The retiree’s
age on December 31 is used to determine the exclusion amount for that
year. Pension income includes both PERA and DPS benefit structure
benefits, Social Security payments, certain other retirement pensions,
and distributions from Individual Retirement Accounts and tax-deferred
savings plans.
https://www.copera.org/sites/default/files/documents/2-91.pdf