I am retired but borrowed money from my retirement plan

[Vanessa A]

What type of plan?

Is this a loan you will be repaying?  If so, then it is not likely taxable as it is being treated like a loan.

Are you keeping the money but older than 59.5 years old.  Then you generally would not be subject to an early withdraw penalty, however, it will still be included in your income as taxable income.  If it was a 401K and contributions were pretax, then the entire amount will be included in your taxable income.

If it was post tax contributions, then you would only be taxed on the earnings. 

Did you take it out to cover medical expenses and are keeping it?  If so, then the amount that is able to be excluded is the amount above 7.5% of your AGI.  This means if you have an AGI of $50,000 then only the amount over $3,750 would be able to be excluded for medical expenses. 

See the link below for other reasons your withdraw may not be subject to early withdraw penalties.

Retirement topics - Exceptions to tax on early distributions

[Opus 17]

You generally can't borrow from IRAs.

If you borrowed from a workplace plan (401k, 403b) that has a mandatory requirement for repayment by payroll deduction.  If you stop working for the employer (quit, fired, retire) then you have 60 days to pay the outstanding balance.  If not, the outstanding balance is considered a distribution to you and you will get a 1099-R from the plan.  You must enter this as taxable income.  If it was a pre-tax account, you will owe income tax, and a 10% penalty if you are under age 55.