Importing 1099-B

when it's ready, yes you can.  if you have issues contact the broker. some require a special procedure to import. 

Thank you.

When will it be ready?

If it's the brokerage, the data should be available now. 

I will verify this though.

Yes, of course !!  To see instructions and discussions, click here: Ameritrade import

If you sold any stocks and bonds transactions during the year, the program will generate either a long term or short term capital gain or loss depends on how long the stocks are being held.  The amount will be reported on line 7 of your Form 1040 along with a Schedule D and Form 8949. 

for best results with TurboTax, use the "enter a summary" option.

As an active investor, be aware that your category Box A or Box D sales without adjustments do not require Form 8949, so there is no reason to import or key in those transactions.
Instead use the "enter a summary" option to put your numbers on Schedule D Line 1a or Line 8a.

Category A and D are the covered transactions.

If you summarize (recommended),

you only need to supply PDF of 1099-B covered transactions with adjustments that are not listed on your e-Filed Form 8949. and all non-covered transactions not listed there.

in other words, for active investors, generally this is a list of the Wash Sales.

Note: turboTax may suppress some covered transactions without adjustments. For those, no mailing is required !
--
If you have two pages (for example) of Wash Sales,
use Adobe Reader to print those two pages. That's all you have to mail to the IRS, given that those wash sales are not on your e-Filed form 8949 already.
(you might enter them manually if they are few in number.)

If you were wise enough to avoid wash sales, you won't have to list or mail anything.
Meanwhile some have reported that TurboTax will take your 1099-B PDF as an attachment avoiding the need to mail it.
TurboTax has not documented or publicized this capability.