Note that I think you meant "5 kHz" not "5 Hz". 154.905 is 154.905 MHz, which is 154905 kHz. (Note also which letters I capitalized: it is Hz, kHz, and MHz. The 'kilo' "k" is not captalized in kHz but the 'Mega' "M" is in MHz--seems many do not know this international standard.) Now to your question, you did not say what radio you are programming and to do what--it can matter. If you are programming a single frequency, it does not matter on most receivers--you can tell if it displays as you want. But in a search over a frequency, it can matter as you do not want to jump over frequencies; and the step-size will depend on the band.
I'm guessing you're talking about an analog frequency step size, right? And if it is analog, yes the 5 kHz step size should work fine for you. In fact, that's what scanners had for decades as the default step size and you couldn't even change it. Now with digital signals there are different step sizes like 7.5 kHz for the VHF Hi band. But even if you use 5 kHz in the digital realm it wouldn't make any real difference because they're so close together you'll still get the signal. But from the frequency you posted, it looks like it could be an analog 5 kHz step size you would want to be using. That should work perfect. And by the way, things have changed a little bit due to the digital frequencies now, but the default spacing between any two FCC licensed frequencies in the VHF Hi band has been 15 kHz historically. In other words, if somebody was using the next frequency up from 154.905, they would be using 154.920. or if they were using the FCC licensed frequency before 154.905, they would be using 154.890. Now with the digital era the step size has gone to 7.5 kHz in the VHF Hi band. Of course that is for the digital frequencies but you'll even find some analog users also using frequencies that have that spacing. Bottom line, you shouldn't have any problems with 5 kHz.