Dealing with cost basis of a municipal bond

[FEDUKE404]

Client bought / held to maturity a $10,000 municipal bond.
On Form 1099-B, the "Proceeds" and "Cost or other basis" both show $10,000 and a net gain / loss amount of zero.
But in the margin, "Original Basis: $10,835.70" is shown with no further explanation.

So, does the client have zero gain / loss as reported (Code D) on the Form 1099-B, or instead has a loss of $835.70 to report on Schedule D?

A likely explanation is a purchase bond premium, but answers from the investment person nor client are not forthcoming. And the firm, as always, hides behind "we don't give tax advice." (Well, it is THEIR tax document. . . .)

Thanks in advance for assistance in how to deal with this matter.

FE

[Uncle Sam]

Can the broker provide a copy of the purchase confirmation so you could see the details?

[Rapid Robert]

"A likely explanation is a purchase bond premium,"

Isn't that the only explanation?

[FEDUKE404]

To further confuse things, the client has several other muni bonds that were NOT held to maturity / redeemed. They were sold during 2023.
The Form 1099-B for each of those shows on the 1099-B dollar amounts different from the underlying bond principals for both purchase / sale, and the net gain / loss is the difference in those two numbers. ***BUT*** there is also an "Original basis" amount (same as my post above) that does NOT match the cost basis reported on the Form 1099-B and subsequently in the Form 8949 totals.

I remain confused. . .

FE

[FEDUKE404]

"A likely explanation is a purchase bond premium,"

Isn't that the only explanation?

Perhaps, but that does not explain why there exists such a "original basis cost" note for the bonds that were redeemed (numbers match bond principal) and bonds that were sold in the open market in 2023 (cost / proceeds amounts on Form 1099-B both differ from the bond principal, and the cost basis on the Form 1099-B does NOT match the "adjusted" amount for any cost basis of the several bonds that were sold.