Key questions;
1. Is your injury service connected by occurring or being aggravated during duty, either Active Duty, or during a drill? AND how much evidence do you have to prove the connection? (not necessarily an LOD but service medical records, etc...).
2. What is the severity of your LOD injury or condition? From what you've said it doesn't meet retention standards. Is it a physical or mental health issue, and can you prove a casual link (connection) between the condition and military service (including off time during Active Duty)?
Sadly, not getting an LOD when you were due one, and being returned to the Guard as an M-Day Soldier after deployment seems to be a common nightmare. If you have any service medical records stating your injury occurred or was significantly aggravated during Active Duty or drill, all you have to do to get the ball rolling is make a formal request to your Unit Commander, requesting the LOD be initiated, explaining how it is service connected, and including your evidence.
Even if as you stated you were treated for a condition or injury shortly after deployment, you should request an LOD, gathering up any statements from fellow Soldiers who know of your injury being service connected, and any other evidence you may have. It will be a much harder sell without the smoking gun of service medical records, but even if you casual link is mostly circumstantial, it's better to put your best effort into it and see what happens. Especially since so much is at stake on whether you can get an approved LOD.
From there the Unit Commander, State and NGB have no choice but to process the LOD even if years have lapsed since the time of the injury. If the evidence is strong enough, the Commander has the option to approve it as an Informal LOD. If not, the Commander will request a formal LOD and there will be an LOD Investigating Officer who will look into it, and more than likely request more information from you.
Key thing to keep in mind about LOD's they are by default IN the Line of Duty, providing there is evidence it occurred during a period of duty, AND is not connected with any act by you of misconduct, gross negligence (meaning a complete lack of common sense such as jacking up a HMMWV with a tankers bar and your helmet and it falling on your foot, not accidently touching the wrong wires together and getting burned, which is simple negligence), or being AWOL at the time of the injury. It is up to the Guard/Army to provide evidence of why you aren't entitled to a favorable determination, and barring that is should be LOD-Yes. Refer to AR 600-8-4.
Beyond that, if your LOD injury (even if you don't have the LOD finalized yet) prevents you from either working in your Civilian job, and/or performing drills, you should be entitled to draw Incapacitation Pay while you are unable to work or drill. If that's the case, let me know on this thread or PM me and I'll explain how you go about working it out. Refer to AR 135-381 and DA PAM 135-381.
As for the difference between 18 years and 20 years in the Guard, it's not all that much if you are only an M-day Soldier. How your retirement benefits will be calculated is by taking your total points and dividing by 360 for a calculation of how many AD years you'd be credited for. It is my understanding that if you're leaving because of medical reasons, (and I'm not sure if it has to be service connected medical reasons) you can get the Retired Reserve benefits starting at age 60.
The big difference is between Retired Reserve and Medically Retired.
Retired Reserve draws a check starting at age 60, and is only qualified for Tricare Retired Reserve insurance (which by law is at NO COST to the Government) meaning you pay the full bill, that's monthly premiums of roughly $390 A MONTH for just yourself or $961 A MONTH for family coverage, that's pretty steep and not including the co-pays.
http://www.tricare.mil/Costs/HealthPlanCosts/TRR.aspx
Medically Retired (30% or higher DOD rating, which is ONLY for those conditions considered Unfitting by the military) and you and your family qualify for Tricare Prime or Tricare Standard (your choice) which is heavily subsidized by the Government, and that's from the first day of your retirement, NOT waiting till you're 60. Just like an Active Duty medical retiree.
http://www.tricare.mil/LifeEvents/Retiring/MedicalRetirement.aspx
If the DOD combined rating (after appeals if needed) is less that 30%, you will be Medically Separated. Then you will be given a lump sum severance check based on your years of service and NO other. Not 100% sure, but I believe since you have 15+ years, you may have the option to waive the severance and go Retired Reserve when you hit 60. I don't know the rules on who gets their severance pay recouped (taken back over time) by the VA, but here's a link.
http://myarmybenefits.us.army.mil/H...e/DoD_Disability_Severance_Pay_.html?serv=147
Also, if your injuries are Combat Related (including instrumentalities of war and simulations of war) you should qualify for CRSC (Combat Related Special Compensation) which IF you are Medically Retired, not Separated, allows you to draw BOTH your VA disability benefits AND a calculated portion of your military retirement AND CRSC benefit.
http://www.dfas.mil/militarymembers/woundedwarrior/disabledretireest.html
Either way (CRSC or not) if your injuries are service connected not necessarily combat related and are rated at least 50% by the VA, when you reach age 60 you should qualify for CRDP (Concurrent Retirement AND Disability Pay).
http://www.dfas.mil/retiredmilitary/disability/comparison.html
So in short to hell with your Option #1, probably NO to Option #2, and best COA is fight to get the LOD and go through the IDES (MEB/PEB) with the goal of making a combined DOD rating of at least 30% and being Medically Retired.
Hope this helps...
