I usually put more into my IRA before April, in fact I believe I have done this EVERY year, once (2015) I did not and now the IRS sends me a bill???? I dont understand
You did not meet the deadline for that year?
Then, you are not eligible for the deduction for that year.
IRS is bound to notice.
Well if you deducted the IRA contribution and then didn't make the contribution then your return was incorrect. . As soon as you realized that you didn't make the entire contribution you listed on your return you should have amended the return asap. But you didn't .... So the IRS recalculated the return using the actual contribution that you made and sent you a bill for the balance due
They sent a bill for WAYYYY more then the "missed" amount tho, as my missed about was only $463 and I got a bill for over $3000
Well then there must have been other items that they caught as well as how the missing contribution effected the rest of the return. You should have gotten a CP2000 notice explaining what they changed... what else did they catch?
There are certainly situations where disallowing an entire traditional IRA deduction could legitimately result in a tax bill of over $3,000. Perhaps you were not eligible to make any of the traditional IRA contribution, making you ineligible for a deduction for the entire contribution (and subject to an excess contribution penalty), or you actually did not make *any* contribution to a traditional IRA for 2015. Check your 2015 Form(s) 5498 from your IRA(s) that report to the IRS the amount you contributed for 2015.
As Critter#2 has suggested, examine the IRS notice carefully.