Retirement tax questions

Rollover was done in 2018 and reported on 2018 Form 1040.  I was issued relevant 1099-R, and followed TurboTax instructions precisely.  I think the issue is with IRS.  Treating roll over as part of AGI is causing Medicare premium to bump up.  I have appealed the increase to Social Security.  I ran the numbers again thru TurboTax, but the numerical outcome is same.  Thanks.