Yes, you can be penalized with a 6% excise tax each year for excess contributions to an IRA, but you can avoid this by withdrawing the excess contributions and any earnings by the due date of your tax return (including extensions). 
 

What is an excess contribution?

An excess contribution is any amount contributed to an IRA that exceeds the annual contribution limits. 

What is the penalty?

If you don't remove excess contributions and earnings by the tax filing deadline (including extensions), you'll face a 6% excise tax on the excess amount for each year it remains in the IRA. 

How to avoid the penalty:

To avoid the penalty, you must withdraw the excess contributions and any earnings from those contributions by the due date of your tax return (including extensions). 

How to correct an excess contribution:

If you discover you've made an excess contribution, you can correct it by withdrawing the excess amount and any earnings by the due date of your tax return. 

What if I can't withdraw the excess by the deadline?

If you can't withdraw the excess contributions by the deadline, you'll have to pay the 6% excise tax each year for every year the excess remains in the account.