Processing Delays

I do taxes for a disabled sibling.  I filed for him back in February and he gets a token refund of a couple hundred dollars.  IRS has been sitting on his return since February.  I check 'Where's my refund" and it's been in 'Processing' state for months and months.   Are they just slow or do I need to try and get in touch with them?   Strangely enough, my state accepted what I filed and they have completed everything.  Maybe they are just assuming IRS is super slow so they just take what I sent them?