When determining the impact of the WEP, the number of years a MainePERS retiree participated in the federal Social Security System with substantial earnings impacts the percentage formula in the first tier of the calculation.
When a MainePERS retiree has between 20 and 30 years of participation in the federal Social Security System, the percentage in the first tier of the calculation is as follows:
| SS Years | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Percentage | 0.4 | 0.45 | 0.5 | 0.55 | 0.6 | 0.65 | 0.7 | 0.75 | 0.8 | 0.85 | 0.9 |
| $826 | $330.40 | $371.70 | $413 | $454.30 | $495.60 | $536.90 | $578.20 | $619.50 | $660.80 | $702.10 | $743.40 |
If a MainePERS retiree has 30 + years substantial participation in the federal Social Security System, there is no WEP.