yes it is confusing but like the above poster says, you can only REDEEM on the partner carrier. What both airlines have allowed in the past--and I believe Delta does still, is the ability to transfer miles to other delta members but for a significant fee of service. the only way airlines ever combine any miles is if one buys out the other. It almost happened once with US Air and AA, and AA was letting people with US miles combine amounts to fly on AA with the AA miles they had, but the deal fell thru and that ended. Now, news reports of US and DL and also United and Co are floating around... Who knows what would happen if these merged! Would someone with 10k in each end up with 20k in one? Let's hope! But that's all heresay... let's talk the reality of your situation as it stands today...

What I would recommend is this:

-tell us what your plan is with travel and where you leave from or go to. This helps because people in here can make recommendations based on what they have seen work in similar conditions, etc.

-tell us how many miles you have in each program. Dont be embarrased. we all started off that way. You are now on your road to an addiction of a new hobby-- I mean assistance and the experience of award travel! Congrats!

-learn of ways to gain miles in those programs using the promotions and deals in here.

Eventually, should you actually devote time and energy to building both accounts up like we all do in here, you will have enough for an award on both airlines. Then you can get two people and book two flights to fly together on awards on the same plane! Example: 25k in CO and 25k in DL... two people fly DL from BOS to Lake Tahoe to go skiing! (that would be ideal)

MM
oh, and welcome to FT!