It varies - but I have seen physiatrists without fellowship training perform lumbosacral injections (ESIs, facets, caudals, etc.), peripheral joing injections (shoulder, hip, knee, etc.), EMGs, SI joint injections, trigger point injections, carpal tunnel injections, etc.
It depends on the job you get. (usually more of a political issue than competency) There are some jobs out there that will actually "train" you to do basic procedures. Most seem to agree that cervicals and other higher risk procedures should be deferred to those w fellowship training. Disk procedures, pumps, stims, etc are probably advanced skills gained best in fellowship.