Turbotax does not charge for an Installment Agreement, the IRS does.
What's New
Expanded use of form. You may use Form 9465 to
request to add the liability for a new tax period to an
existing installment agreement. You may also use this
form to request an installment agreement for the individual
shared responsibility payment.
Updated fee amounts. Beginning January 1, 2017, the
fees for setting up an installment agreement are $225,
$107 (if you make payments by direct deposit), $149 (if
you set up an online payment agreement), or $31 (if you
set up an online payment agreement and make payments
by direct deposit). See Payment methods on page 2.
There is an $89 fee to modify or reinstate an installment
agreement.
For low income taxpayers, the fee to set up an
installment agreement is $43 or could be $31, if an online
payment agreement is set up and the payments are made
by direct debit.
https://www.irs.gov/pub/irs-pdf/i9465.pdf
