You need to wait to receive the actual K-1 before completing your return.
The letter is telling you what you could expect to see on the K-1.
This is also telling you that you may not receive your K-1 until after April 15th, so you will need to use the amounts in the letter to prepare an extension and possible payment along with the extension.
*A reminder that posts in a forum such as this do not constitute tax advice.
Also keep in mind the date of replies, as tax law changes.
