Part 65.61.d.2 IFR Requirements I have a question regarding this requirement as I work on my IFR SEL rating:


  Forty hours of actual or simulated instrument time in the areas of
  operation listed in paragraph (c) of this section, of which 15 hours
  must have been received from an authorized instructor who holds an
  instrument-airplane rating, and the instrument time includes [...]


The question is, if 15 hours of the 40 hours is required to be with an authorized instrument rated instructor, then how do you gain the other 25 hours of the required 40 hours?  Wouldn’t all 40 hours have to be with an instrument rated certified instructor?
If you're under the hood in VMC + VFR, you could have an appropriately rated pilot (i.e. PPL) in the other seat as the safety pilot. If the other pilot is instrument rated (but not a CFII) + is the PIC for the flight, you could even be the sole manipulator of the controls in IMC + IFR, although that gets into the questions about logging PIC vs acting as PIC, which is its own set of issues. The "safety pilot" option is probably more typical.