Can I change the dollar amount on form 1099-DIV for line 1b (qualified dividends) based on supplemental information I received?

[alj]

Vanguard sent me supplemental information saying that "100% of the short-term capital gains distributions of certain funds are qualified short-term capital gains distributions (QSGs)". A municipal bond fund of mine is one of those funds.
The short-term capital gain distribution is not included in line 1b (qualified dividends), only on line 1a (total ordinary dividends).     
Am I able to change the number in line 1b to reflect this supplemental information? What concerns me is this will be different from the Form 1099-DIV that the IRS receives, with no explanation.

[JohnB5677 · Accepted solution]

Occasionally, a 1099-Div may need to be corrected. When a 1099-Div is incorrect, you need to respond quickly to correct the error. 

If the institution identifies the error, then you should receive a corrected 1099-Div.  Contact Vanguard and see of they are going to issue one.

If Vanguard is not going to issue the corrected copy, you can still make the change.  However, as you said.  It will not match what the IRS has. 

That's okay, but you may get a tax notice asking you to explain why you made the change.  You can then respond by providing the notification that you got from Vanguard.

If you've completed your tax return; you may need to file an amendment.

You can correct a return that you've already filed and had accepted.  

Select your tax year for amending instructions:  2020