DSM stands for Diagnostic and Statistical Manual of Mental Disorders and V is the latest edition used to diagnose a number of mental disorders including ASD.

http://www.autismspeaks.org/dsm-5/faq

In DSM-IV, there were three core impairments needed to qualify for autistic disorder diagnosis - impairment in language, repetitive behaviours and social. If you had impairments seen in only two of the three, I believe it was typically diagnosed as PDD-NOS. I believe in DSM V, there are only two core areas - impairment in social and repetitive behaviors. So language/communication as a standalone category is gone and believed to be covered as part of impairment in social communication. Accordingly to one study, 80%-90% of those previously diagnosed Aspergers or PDD-NOS would still retain ASD diagnosis.

If impairment is not seen in repetitive behaviors and only social impairment seen, there is a new category called social communication disorder (10% of Aspie or PDD-NOS that didn't quite the make the clinical cutoff for ASD fell into this new category). This new disorder is not part of ASD.

For us, I doubt it would make any difference at all and we don't get any free services anyway, so it is not relevant.

It would be pointless to retest him. If they already know he has autism, he doesn't need an Asperger's diagnosis.

An up-to-date clinician wouldn't be diagnosing Asperger's anyway since it is not technically a diagnosis anymore.
The newer diagnosis would just be Autism Spectrum Disorder (ASD), which includes the now outdated Autistic Disorder, Asperger's Disorder, PDD-NOS. the only difference now is severity. Services and therapies are based on individual needs, rather than the diagnosis anyway.

Thank you for the help. But what is DSM V? He has PDD_NOS. Is that. Any differnet?

I agree with Everything here. It is so hard to deal with all this.
I feel the same about my dd but I was told having the ASD vs aspergers there is more support.

There is new DSM V now for autism spectrum disorder. There is no aspergers or PDD-NOS diagnosis anymore. So if you retest, it is possible he may be classified as ADHD only, or perhaps still within ASD. These may impact eligibility of services obviously, so need to keep that in mind as well.