By Martin Wolk

If you are underwater on your home or struggling to pay your mortgage, you are probably wondering whether you can expect relief under a $25 billion settlement reached by state and federal officials with the nation’s biggest banks.

The short answer is, you probably won’t know right away.

According to details laid out on a new “National Mortgage Settlement” website, the payments and other relief will be made over a three-year period and “borrowers will not immediately know” whether they are eligible.

There are three main categories of people who will be aided under the settlement, according to the site:

Homeowners who need loan modifications to stay in their homes. Loan servicers have agreed to write off some principal in these cases, which would help homeowners refinance at lower monthly payments.

Borrowers who are current on payments but underwater, meaning they owe more than their home is worth. Servicers will help some of these owners refinance at current rates, which are at or near record lows.

Borrowers who have lost their homes to foreclosure. Some of these former owners will be eligible for payments. $1.5 billion will be distributed to 750,000 borrowers, which works out to $2,000 per person.

Within the next 30-60 days, an administrator will be chosen to oversee the settlement. Eligible homeowners will be identified over the next six to nine months, and will be notified by mail.

The settlement largely affects borrowers whose loans are serviced by five big banks: Bank of America, Citi, JPMorgan Chase, Wells Fargo, and Ally/GMAC. Loans owned by government-owned mortgage giants Fannie Mae and Freddie Mac are not affected. Borrowers from Oklahoma also will not be eligible because officials from that state did not join the settlement.

For more information. including telephone numbers of the loan servicers, check out the settlement website. The site also includes links to check whether your home loan is owned by Fannie or Freddie.

What the mortgage settlement means to you.