It depends bud.
Less than honorable is divided into four catagories with each progressively more harsh. The order is General, other than honorable, bad conduct, and dishonorable. The last two requireing a court martial.
All four indicate loss of certain benifits with General usually meaning most benifits are elible and the last two meaning none. Less than honorable falls into the gray area of maybe, maybe not. Alot of this has to do with the date of service. Certain reasons for other than honorable discharges were deemed illegal with automatic upgrade to general qualified while others are not depending on the reason.
Eitherway, the odds are high benifits will be denied in todays climate. That's the bad news. The good news is that this type discharge is the most fequently upgraded to general. You can start this process by visiting your local VA office and ,surprise, filling out the appropriate DD forms and applying for an upgrade. If I recall it's DD239 and after 15 years since your ETS date form DD149. Form 149s have a higher success rate for upgrade than 239s. Legal representation on 239ss tend to do better than not and no legal representation not as much a factor on 149s. It follows 149s get approved for upgrade to general faster than 239s.
If your friend does not fall into the automatic approval catagory such as discharge for drug testing pre-1979, then I wouldn't be surprised if it's denied the first time and an appeal necessary.
Please keep in mind, I'm not a VA official but only an appointed VA administrator volunteering to help disabled vets and this post just from my personal experience. Personaly I find whole thing a tad confusing with little rhyme or reason. Most of the vets I have worked with were combat vets so tended to do a tad better on these type issues than those who weren't.
The first step to finding though is visiting your local VA office and first asking the question then starting the process. Your VA office will give the best advice for your area and yes the area has a lot do with it such as representatives, federal judges, etc.
Complicated I know but hope it helps.
BTW, If anyone wonders why I took the time for this post. It is simply because I see those with less than honorable discharges as those who at least tried and have known more than my share of guys who fought and risked all for this country with these type discharges. Most notible in my life was my Senior Drill Sargent in basic who after three tours in Nam got a Dishonorable for trainee abuse but IMHO he not only did his duty where it counted but indirectly saved my life by hammering his hard learned lessons home.