You should apply the lime before you lay the Loam. Hopefully the new loam you get has a close to neutral Ph. Remember, It takes time to adjust the ph of soil. One application of lime will help, but you will have to apply lime yearly for a few years if your soil is really acidic. Don't over apply the lime in hopes of raising your ph dramatically. Over application will only cause further problems. Its better to apply smaller amounts over the course of a few years. I would apply the lime ASAP. Its recommended not to apply lime and fertilizer together. Give the lime at least a month before applying fert.

"The whole reason I have the moss is because I have extremely acidic soil"

I don't think so. I keep reading that acidic soil is what leads to moss, but I have alkaline soil and along the fence with my neighbor who waters too much, I get moss all the time.

I'm pretty sure the moss is caused by too much water.

I'm not sure I'd do anything before adding the new soil and giving it a chance to get settled, then doing a soil test. How deep a layer will the 20 cu yards be? If it's only 1/2 inch or so, I'd amend the soil before adding the soil, then fertilize after adding it. If it's a couple of inches, I'd wait to see how it shakes out, since that will be the soil you need to test in the future.

I will be adding 2-3" of loam. The area the moss started or where I assume it started was under a tree that has since been removed (before I bought the house). In this area, the moss is 2-3" thick. It's insane. I had to use a pincher bar to break through it. A shovel wouldn't break through. As I posted, I don't think it had been aerated in a very long time and it seems to be very compacted which would lead to a drainage issue. Thus your "too much water" statement is correct. I have a whole lot of different issues going.

If you're adding 2-3 inches of loam, you're really changing much of the soil that you're going to be growing your grass in. I think it would make more sense to wait until you have that soil in place before testing to see what you've got. You could probably add lime after scraping off the top layer and before adding the new soil to treat the soil that is there now, but I wouldn't fertilize that soil, since it will take some time before the grass roots are long enough to get past the new soil you add.

It might make sense to get a soil test next year to see what you've got after the new soil has been in place for a while and things have stabilized a bit.

That is probably what I am going to do. We just got a price to remove the moss, add 4" of loam and hydroseed a 3000 sq ft area for $1350. I think that's pretty good...seeing most places wanted $700-$900 just to remove the moss.

...hmmm, 150 pounds of calcitic lime, $18; 10 pounds KBG, $50; 1/2 day rental of aerator, $45; 3 yds of soil/compost mix, $75. Your deal doesn't sound like a deal to me.

I don't understand importing the amount of soil you stated. Is there a grade problem? Generally you are better off improving what you have than importing problems, but I'll assume you've checked the reputation of the company you deal with.

How will you irrigate and what is your current routine?

How much sun does the area get?

I don't know if you read my entire post or not, but the stuff is 2-3" thick and I had to use a pincher bar to break through it. A shovel does nothing. There's no "correcting the problem" that can be done now. I have to start from scratch. The area I am talking about is about 3,000 sq ft and 80% of it is this thick moss. What you are suggesting will not fix my problem any time soon and I have a 1 1/2 year old who is just dying to use his backyard. We've had at least 8 different lanscapers out and none of them have suggested we leave it and try to treat it. It's just too bad.
1. Currently I don't water because it's just moss and crabgrass and dirt.
2. The area get's an even mix of sun & shade throughout the day.

The base of trees where water pools is the only place I get moss too. It is not as bad as yours though and since I've been core aerating, has not come back.

Your $1300 estimate sounds pretty darned good. Hopefully it is a reputable company. Some might just bury the moss, give you far less than 4" loam, etc. You might also ask if they can make their hydroseed mix out of see you provide, to ensure better quality seed.

Yes, I read your post - multiple times and your previous post on rototilling it. I just don't understand what you are calling moss. Every moss I've ever dealt with is very fragile, easily skimmed off, and responds to cultural practices. What I offered you is an alternative, but your choice is your choice. If you don't fix the problem of why the moss is there to start with it will return.

Let us know what happens on this -- curious as to what will work!

skoot_cat, not trying to hijack kgrant's thread here, but why do you not say it's not recommended to apply lime and fertilizer together? I will be working on restoring a lawn soon, and the soil is very acidic (4.7 - 5.2). We are going to start from scratch with it, but need to start working on bringing the pH up. I was going to core-aerate, lime, seed, and then fertilize (in that order). The extension agent that gave recommendations based on the soil test said nothing about not applying the lime, seed, and fertilizer together. Thanks!