If you have a Qualified Annuity (that is, one intended to give you a Tax break, if you wait until the normal starting date) then you'd have to pay Income Taxes on part of the payments, if you pulled it out now. There's a formula, but here's an example: Say you take a $50,000 distribution from the annuity before the annuity starting date. Say you had $10,000 invested (your "cost") in the plan. Say, at the time you pull out $50,000, your account balance was $100,000. In that case, you can exclude $5,000 of the $50,000 distribution from Income Tax, but have to pay taxes on $45,000. The formula is as follows: You multiply the amount you pull out, by a Fraction. The fraction is the amount you invested in the annuity (your "cost") divided by (over) the total amount in the annuity at the time you pulled part of it ($50,000) out early. Whatever you get after doing this is the amount you can exclude from income tax, but you will pay tax of the rest of what you pulled out. Of course, if you pull out the entire annuity, you would pay income tax on everything except the amount you invested (put into it yourself, which is your "cost." Those are the rules for a "Qualified Plan," such as a retirement plan set up by an employer.
If it happened to by a Non-Qualified plan (something you bought on your own as an annuity) then it's the same if you pull the whole thing out. If you pull only part of it out, you would get taxed on all of that part, as long as it would be included in your earnings under the annuity. But once you went beyond what your investment earned, you'd have no tax on your investment part.