2020 HSA Limit Married Joint Over 55

That is because it  is an incomplete program and it will not be fully operational until sometime in January or February for some things like states.   The program will undergo weekly updates as they complete sections ... this happens every year without exception.  

ANY tax software released by any company prior to about January 15 is only released for marketing and market share.  No program is complete and ready to file until the IRS approves their final forms and then individually reviews each program's implementation of the form.  And some tax situations aren't able to be filed until February or March, again mostly due to IRS delays.

The HSA contribution limit is one of the dozens of inflation adjustments for 2020. TurboTax will not update it until after the IRS releases the final Form 8889 and instructions for 2020, which they have not yet done. The Form 8889 that is in the preliminary version of the software right now is not final and cannot be filed.

the $8100 is correct only if contributions are to 1 a/c - $7100 max + $1000 for over 55.  assuming you qualify to have your own HSA a/c you can make a contribution to it of $1000 if you are also over 55. 

I noticed the same issue... TurboTax Premier shows an $8100 HSA contribution (family and over 55) as having $100 excess contribution.  It appears that the 2020 program is still using the 2019 HSA limits and has not been updated yet.

I NOTIFIED THEM OF THE ISSUE