Green Book
PM-10 (1987) Maintenance Area (Redesignated from Nonattainment) Summary
As of September 22, 2016| Classification | Number of Areas | Number of Counties | 2010 Population |
| Serious | 5 | 15 | 22,002,469 |
| Moderate | 47 | 52 | 9,573,185 |
| SUBTOTAL | 52 | 66 | 31,575,654 |
| GRAND TOTAL | 52 | 66 | 31,575,654 |
County subtotals and grand totals may not equal sum of parts. Part counties are only counted one time within groupings. Multi-state nonattainment areas are not considered maintenance areas until all states in the area have been redesignated