The coalition says that two-thirds of the nation is "well-housed at costs that are well within their households' budgets."
The other one-third, though, "must devise ways of coping that at a minimum mean forgoing all optional or postponeable (sic) spending or saving, too often require making impossible choices among necessities, and in the worst case, managing with no home at all," the introduction says.
The report says the national standard for affordable housing is no more than 30 percent of income.
In Washington County, 30 percent would be $408 a month, the report says.
But the fair market rent for the county is $482 for an apartment with one bedroom and $616 for an apartment with two bedrooms.
Other Tri-State counties have similar deficits, the report shows.
The 30 percent level in Berkeley County, W.Va., is $402 a month, or $111 less than the fair market value for a one-bedroom apartment, which is $513.
Frederick County, Md., had a $404 gap - $641 for the 30 percent level of monthly income compared with $1,045 rent for a one-bedroom apartment.
In Franklin County, Pa., the difference is negligible.
The 30 percent level for affordable housing there is $404, while fair market value for a one-bedroom apartment is $416, the report says.
The number of U.S. counties in which someone earning minimum wage could afford a one-bedroom apartment - assuming the 30 percent level of income - used to fill a computer screen, said Katie Fisher, the coalition's media coordinator.
This year, only four counties qualified, she said.
There are no counties in which the fair market value for a two-bedroom apartment is within range for a full-time minimum-wage employee, the report says.
"Out of Reach 2004" includes a wealth of income and housing calculations, including how many hours a minimum-wage earner must work per week to pay for a two-bedroom apartment.
To pay for that apartment, someone making $5.15 per hour has to work 69 hours in Fulton County, Pa., 76 in Morgan County, W.Va., 78 in Franklin County, 89 in Jefferson County, W.Va., and 92 in Washington and Berkeley counties.
The task is theoretically impossible in Frederick County, where, according to the report, it would take a 177-hour workweek - nine hours more than are in an actual week.
Some states have their own minimum wage, but Maryland, Pennsylvania and West Virginia each has chosen $5.15 as its rate.
The report defines "housing wage" as the pay someone needs to afford a two-bedroom apartment while working a 40-hour-a-week job.
West Virginia's housing wage is $9.31 and Pennsylvania's is $13.82.
Maryland's housing wage is $18.25, or about 3.5 times the federal minimum wage, the report says. It's ranked as the fourth-most expensive state.
The national housing wage is $15.37, or $31,970 a year, the National Low Income Housing Coalition says.