I have the CD version of Turbo Tax, and every year when I file my taxes, a summary "Electronic filing instructions" is included. Where is it for the 2018 tax year?

I'm using Windows PC, so your mileage may vary.  Printing is probably a bit different with your Mac, but the principle is the same.

You should be able to get it a couple of ways.

It should be in the PDFs of your return that you can make this way:

When you print the return or make a PDF, you should get a print preview screen where you can choose "All official forms required for filing"  or "Forms to review to keep for your records."  You can view that PDF and print out what you need.  Both of those choices have the Filing Instructions.

Or to view/print just the Filing Instructions, in that Print Preview window choose the option "Specific form" and put a checkmark for Filing Instructions (there may be 2 pages.)  

OR you can use this alternate method:

Go into Forms Mode.   In the forms list in the left column scroll down near the end of the Federal forms and you'll see the shortened name "Filing Inst",  possibly 2 pages.

If you have a state return, then look near the bottom of the state list of forms for the state Filing Instructions.

Thanks for the suggestions.  I did try all of our recommended actions and none of them worked for me. I have the 2018 Turbo Tax Home and Business edition and I had the 2017 edition last year and it did generate those forms.  I cannot find it anywhere in 2018's version.  Very annoying - if they did omit it , they should include it in the future for consistency.

Even stranger is that they generate it for the State taxes, but not for Federal

I'm sorry, but I have never seen that happen.

I can only speak for the Windows version, but in TurboTax for Windows, even in a brand new return the Filing instructions form is there, but is blank for a lot of information.  I just tested it.  Right after opening a new return and before making any entries, if I go to Forms Mode, then "Filing Instructions" is already listed as a form in the list.   It is a default form that is always present at any stage of preparation.   However, it originally says "File by Mail" as a default until one actually goes to the FILE section and chooses efiling.  At that point the title changes to Electronic Filing Instructions.   But the form itself should always be there in the list.

I'll see if SuperUser @macuser_22  has any comment on what you are experiencing in the Mac program in case there is a different way it is handled there.

Does your desktop software show that your efiled return has been accepted?   You can also use this tool to check:
<a rel="nofollow" target="_blank" href="https://shop.turbotax.intuit.com/efile/efile_status_lookup.jsp">https://shop.turbotax.intuit.com/efile/efile_status_lookup.jsp</a>

If you choose the e-file option and then printed for your records it should be the first page.

If you use File -> Save to PDF it should be the first page.

If you use File -> Print -> select  selected forms and check the first box (instructions) it should print.

Right, I've never had this happen to me before either, so I thought it was strange too.  The first page that is listed for printing in my e-file option is my tax return.  I don't know why.  

I finally figured it out - I checked for a software update, and after the install, it did appear - hopefully it didn't screw up my taxes without it.

Had your Mac not been auto-updating every time you ran TurboTax?

It had when I first opened the software, but I guess it never installed it correctly, because I went to check again after all this happened, and it was there.  I didn't think to reboot the program, and I should have done that first.  Thanks for all the help!

If it was behind on updates, you should check to see if anything changed in your return.