When doing the Maine Tax Return, Turbotax is only giving a $2500 credit for Student Loan Repayments when it should give a one-time $3500 credit (the STEM box is checked).

You are using the online program so I wonder if you have a piece of data stuck.

You are correct. $2,500 is the limit unless you qualify for an exception, which you do. 

A full or corrupted cache can cause problems in TurboTax, so sometimes you need to clear your cache (that is, remove these temporary files).

For stuck information follow these steps:

1. Delete the form, see How to Delete  
2. Log out of your return and try one or more of the following:
   • Don't use Internet Explorer.
   • Clear cache and cookies,
   • Sign in using a different browser.
   • Sign in using a different device.
3. Log back into your return.
   • Enter the form again.

When going through the Maine return, you must select YES for credit for Student Loan Repayment, when you enter the type of degree, to get the $3500, you must mark degree in STEM.

Please see  page 2 for the new rules this year - bottom left corner.