FMR is set at the metro area level. SAFMR is set per ZIP and is more accurate for voucher payment in high-opportunity neighborhoods.
FMR vs SAFMR β a quick primer
Fair Market Rent. One rent figure covering an entire metro area (HUD FMR area). Used in most of the country.
Small Area FMR. A separate rent figure for each ZIP code within a metro, set at the 40th percentile of rents in that ZIP. Used in ~24 mandated metros and a growing number of opt-in PHAs.
Payment standards are set by each PHA between 90β110% of whichever FMR (or SAFMR) applies β with HUD approval up to 120%. See Payment Standards for the actual subsidy amount.