Since my 1099-B has more than 3000 transactions from Motif Investing, TT cannot import it and tells me to mail in 8453 form with 1099-B. But the 1099-B is 326 pages long.

Using the summary entry option use the "short hand" entry method ... make ONE entry called Short Term covered, one called Long term covered.... and use the word Various for date purchase & 12/31/18 for sale date.

Then enter the non covered sales either individually OR  again make the general short/long term entries by doing this  you ONLY have to mail in the non covered  pages from the broker statement which should only be a few pages which is very easy to do. I have done this in my business for years successfully.

Yes, you can use summary totals which should be long term and short term transactions. You can further separate by covered and noncovered if you choose.  Regardless of how you choose to do it you may want to file Form 8453 and a copy of your 1099-B, after your tax return has been accepted. You can also wait to see if the IRS does request it later, if TurboTax doesn't indicate you should file it.  See the information below if you want to mail now.  Review the wash sale rules below.

Wash sales cannot be combined into section totals.  They should be entered individually so that you can track your cost basis and know when you are allowed to use the information on a final sale.

Wash Sale Rule Defined:

• A wash sale occurs when an investor sells or trades a security at a loss, and within 30 days before or after, buys another one that is substantially similar.
• It also happens if the individual sells the security at a loss, and their spouse or a company they control buys a substantially similar security within 30 days.
• The wash-sale rule prevents taxpayers from deducting a capital loss on the sale against the capital gain of other stock.

Affect on Cost Basis:

• The loss that occurs on a wash sale is added to the cost basis of the shares purchased that created the wash sale.
• When all shares are sold and there is no repurchase, that increased cost basis will be used in full and used to determine gain or loss.

As long as you are tracking the wash sales and are not using them on the tax return when you are not allowed, then you can simply enter the same cost basis as the selling price. This will  reconcile your tax return with your Form 1099-B Proceeds which is what the IRS is comparing.

Wash Sale ends:

The wash sale disallowed is not added to the net gain/loss rather it is adjusted and suspended so that it does not affect the total gain or loss for any pending wash sales.  The rub is that the broker only knows when a wash sale occurs, not when a wash sale no longer exists. This can spill over between two tax years.  Likewise you can have a wash sale during a tax year, and then fully dispose of the stock in the same year which would eliminate the wash sale rule for the final sale of the same stock. 

It's up to you to know when you no longer have to consider the wash sale rule. 

Example: 

X bought 5 shares of ZZZ stock, at $5 per share, then sold it for $3 per share, however immediately before the original 3 shares were sold, X bought another 5 shares at $5.00 per share.  

     $25 for the first block of shares

       15 is the proceeds creating a $10 loss 

The $10 loss is now added to the cost of the new shares for an overall cost basis of $35.  

Once the second block of shares is sold (5 shares with cost basis of $30) without any repurchase with in the 60 day window (30 days before or 30 days after the sale), and if they are sold at a loss, then no wash sale exists on the sale, and a loss is allowed.

If you are e-filing your tax return, then mail your statements (1099-Bs or other document showing detailed sales information) along with Form 8453 to: 

Internal Revenue Service

Attn: Shipping and Receiving, 0254 

Receipt and Control Branch 

Austin, TX 73344-0254

If you need a blank Form 8453, you can download this pdf, enter your address information and check the box for Form 8949 (this form is really just a cover sheet)

@mister_ee_man