You don't send the form to the IRS, it is only for your records.
If you made IRA contributions, you are required to list those on your tax return. Since returns are due in April (or May, this year), but brokers are not required to send the 5498 until after the regular tax deadline, you have to put your IRA contributions on your tax return based on your other financial records.
If if turns out that the information you put on your return was wrong, and does not match the 5498, you may need to file an amended tax return. However, if the information matches your tax return, just file it with your other important tax papers, which you should be keeping for at least 3 years.
