I'm in middle of an IST but haven't found a gaining unit. I'm running into financial trouble after changing jobs. How could I go active duty?

I will assume don't have close to 17 yrs of active duty. In the reserves and guard that is still possible. Go see your career counselor and a recruiter. You will have to do a 4187, get a conditional release and need a counseling statements stating if you don't go you are still in the guard. If you are close to the end of your control just see a recruiter and they will do the paperwork and once your contract ends and you ETS out you can enlist. Those are the 2 options that I know of. And what I was told how to do it.

Is there no IST coordinator helping your process in your state? There should be one in both losing state and gaining state to help facilitate the transfer, by way of seeing what units are there and talking to Readiness NCOs about their manning levels and projected losses. There may also be the possibility of you drilling with a unit that's based in the state you have moved to/are moving to in lieu of drilling at your current assigned unit, but that's a coordination piece between the units, as well as sympathy of the chain of command, as some will be more lenient than others about needing to drill at the unit regardless of state/country living in. Some states are black holes when it comes to ISTs being handled in a timely manner as well, depending on IST managers and size.

As far as going to active duty, you would first need to seek out a recruiter. As the active force is hurting for numbers, they might be more than ready to take you in as a prior service gain. Once you hammer out details with them as to what you're looking for (reclass, duty station of choice, etc), they will give you a DD Form 368. This is signed by both you and your recruiter in section 1. This then goes through your company. As each state may be different, I can only expand on my states process. Your unit Admin NCO would be the knowledge base for your request. My state requires the 368, a DA 4187 sent forward to be approved at levels all the way up to the state G1, clearance of all gear turned into supply, and a DA 4856 counseling you on possible loss of bonus and incentives (if applicable) among other things. Depending on time of year you submit (due to "managed losses") this could take some time to filter up and be approved. The G1, if blessed off on in section 2, will also add an expiration date (normally 90 days), meaning you need to have a new contract signed before that date. When you ship out (driving, flying, etc) from MEPS, the certifying officer there completes section 3 of the 368, and that and your new DD4 packet is supposed to be returned either to your unit for routing or to your state G1. Your unit or state then initiates a discharge from the National Guard fully releasing you over to the service component you chose.

Depending on your state, and who you have working, both of these could be lengthy processes. I've witnessed both take up to a year, and also be processed within 1 1/2 months. Its a gamble either way.

Go to an active duty recruiter ASAP.