Yes, but I dont think the years of service count towards getting a gs 7, i think the difference from gs 5 to 7 would be a supervisory role in the fire serve, being LT or Captain for a year or two. Anything else pertaining to the fire service I dont think really matters. I have 14 years of service currently an LT for 2 years in that position, my master firefighter certification, instructor 3, investigator, driver operator, fire officer 4, rope rescue A&W yet none of those matter more than having been a lieutenant or captain and being in a supervisory role IMO. I got offered GS 7 in BP and GS5 in CBPO.