The three prior posts were correct. You can accept the entire amount of the rollover as income in 1998 or spread it over four years. Either way, some will almost definitely be pushed out of the 15% bracket.

My bigger concern is that you understand what the tax impact will be so you don't underestimate what you need to pay. This might result in having to pay taxes from the rollover itself if you don't have sufficient funds outside the IRA to handle it. That would be a critical mistake which is far, far worse than just getting hit with a higher tax rate.

And to JackPoint:

Who is YMMV?