Have you even tried to look up anything about electric vehicle credits?

You could start by searching the forum. There are several threads going.

"and has been provided an IRS Form 15400 stating the Maximum credit is $7,500. Is there a Federal"

Yes, you just pointed out this IRS form is for Federal.

You can look up the requirements and eligibility at:

https://www.irs.gov/credits-deductions/credits-for-new-clean-vehicles-purchased-in-2023-or-after

and:

https://fueleconomy.gov/feg/tax2023.shtml

But it seems you have the right form, already, as evidence your taxpayer has been reported:

https://www.tesla.com/support/ira-clean-vehicle-report/2023

MD has an excise tax credit:

https://mva.maryland.gov/Documents/VR-334.pdf

https://mde.maryland.gov/programs/air/mobilesources/pages/zev.aspx

• Federal Income Ta​x Credit up to $7,500 for the purchase of a qualifying Electric Vehicle or Plug-in Hybrid.
• Maryland Excise Tax Credit of ​$3,000 for qualifying zero-emission plug-in electric or fuel cell electric vehicles. ​​

Thanks very much for the information for the MD EV Buyer Excise Tax Credit. It is important to note this appears to be a form to be filled out by the purchaser separate from their income tax filings. 

Given the application to receive this credit has a finite pool of monies, it would seem the dealer should fully explain to the purchaser at the point of sale.

Thaks again for the quick responses!!!