Prevailing wage terms, in plain English
The vocabulary of Davis-Bacon work, minus the regulatory prose. For how the pieces fit together, see how WagePin works.
Prevailing wage
The minimum hourly wage and fringe package that must be paid to each class of laborer on a covered public construction project, set by the Department of Labor from local wage survey data. On federal jobs this comes from the Davis-Bacon Act; many states run their own versions for state-funded work.
Wage determination (WD)
The official document listing prevailing wage rates by labor classification for a specific area and construction type. Your contract incorporates one, and it, not the current SAM.gov page, is what you must pay from.
General decision number
The ID of a wage determination, like MN20260001: state, year, and a serial number. A new number is issued each year even when the underlying area and work type are the same.
Modification (revision)
A numbered update to a wage determination published by DOL during the year. Rev 3 of MN20260001 is the same determination with updated rates. Whether a modification applies to your project depends on when it was published relative to your bid opening.
Annual supersession
The yearly rollover where a determination is replaced by a new decision number (MN20250001 becomes MN20260001). Rate changes concentrate here, and the old number stops appearing as current, which is why bid-time evidence disappears if nobody archived it.
Fringe
The benefits portion of the prevailing wage, listed separately from the base rate. You owe base plus fringe for every covered hour, paid as bona fide benefits or as cash on the check. Pricing labor from the base rate alone is the classic new-estimator mistake; the Total column on our rate pages exists so it never happens to you.
The ten-day rule
From FAR 22.404-6: for sealed bids, a modification published ten or more calendar days before bid opening applies to the bid; published later, it generally does not. This is the rule that decides which revision governs your project, and the one WagePin applies when you pin a bid date. Full walkthrough on how it works.
Bid opening vs. award
Bid opening is when sealed bids are unsealed and read; award is when the contract is actually signed, often weeks later. The distinction matters: for sealed bids the wage determination locks at opening, but if award slips more than 90 days, newer modifications become effective. In negotiated procurement, modifications apply right up to award.
Classification
A labor category within a wage determination, like ELECTRICIAN or POWER EQUIPMENT OPERATOR: BULLDOZER, each with its own rate and fringe. Workers must be paid at least the rate of the classification matching the work they actually perform.
Certified payroll (WH-347)
The weekly report a contractor files on covered jobs proving each worker was paid at least the required prevailing rate, commonly on federal form WH-347. This is after-award compliance; WagePin works the other side of the award line, telling you what the rates are before you commit to a number.
Plain-language summaries, not legal advice. The FAR and your contract documents govern.