Simple question. If I get a permit today of myself and one other, is there a way later to add more members to my party?

Thanks!

No problem, when you pick up your permit the other people on your permit get added and then they will pay at that time. I normally only put two people on the permit to hold it. Then adjust at the day we enter at the outfitters.

Go to your reservation on recreation.gov site.
Reservation Details -> Modify Permit -> Add Members.

What Savage Voyageur says.

Also, you can add (and remove) people online up to the day before you pick up your permit.

No need to complicate matters. You will be charged for 2 anyway (who knows why?), so put down one alternate. I name 3 alternates on our men's group trip since I'm playing with the group's money. What's $32 more among friends? The number actually going in can be added (or subtracted) on the day the actual permit is picked up.

^ that was exactly my thinking this year, i put down/paid for four of us

Thanks for the help guys!

One thing to consider is that I am pretty sure Alternate Group Leaders can only be added at the time a permit is reserved and not later - whether one day later or your entry date.