I didn’t know I could file taxes while on disability to get the tax credits. Can I file for the previous year?

[xmasbaby0]

Not sure what tax year you are asking about or what credits you are hoping to get.   Can you be more specific?   If your only income has been Social Security disability, you are not required to file a tax return, nor are you eligible for any refundable credits.   The only tax year in which you could get the refundable amount of the child tax credit was tax year 2021.  For that year you could get the "additional" child tax credit even if you did not have income from working.  After that year, the law changed back to the old tax law, and the refundable credits are available only if you have income from working.