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.
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