The Social Security Administration, the Centers for Medicare & Medicaid Services,
            and State Medicaid certifying agencies must work together closely when de- certifying
            Medicaid facilities.
         
         Although decertification is prospective rather than retroactive, overpayments or underpayments
            will occur if SSA delays decertification notifications and SSA does not adjust Supplemental
            Security Income (SSI) payments (including federally administered State supplementary
            payments) beginning with the month of decertification.