I itemize every year, though I am retired, but my CPA says the IRS limit is $300/yr.
If you do not itemize using Schedule A you can only deduct $300 a year in charitable contributions. If you itemize you lose your standard deduction so it is not worth it for many if not most taxpayers. My guess is that the standard deduction is greater than all of your itemized deductions so your CPA is correct for you.