Are you trying to pursue a personal injury claim, but concerned about your finances? There are a few major ways that a personal injury attorney usually arranges payments: retainers, flat fees, hourly rates and contingency fees. Of these, you usually want to find a personal injury attorney who will work on contingency -- but that isn't always true. The most important thing is to find the personal injury attorney most capable of winning your case.
A retainer involves a specific amount which is set aside to the attorney before they begin. The retainer is generally negotiated based on the amount of work the attorney believes they have to do. The retainer operates as a sort of "deposit"; the labor may still exceed and be billed beyond the retainer amount.
A flat fee rate is generally used by an attorney on a monthly basis, especially for clients that would be prohibitively difficult to track hours for. If you need a lot of work from your attorney and will be in and out of their office, or if you need very little work from your attorney, a flat rate may make things easier for both you and them. The value of a flat rate is that it is so predictable; you don't have to guess how much you'll need to pay your attorney from month to month until the case is through.
Hourly rates are usually charged in fifteen-minute increments, although some attorneys charge by full hours or half hours -- it's always good to specify at the start in order to avoid a misunderstanding. An hourly rate can actually be better than a flat fee rate because it allows you flexibility. You can use the attorney as much as you need; you pay less if you need them less and you have the option of paying them more if you need to talk to them more.
A contingency fee means that you generally do not pay anything unless the personal injury attorney wins your case. That is, obviously, beneficial for many people because you won't need to pay any fees upfront. Contingency fees are fairly rare, but there are some attorneys who operate on contingency fees when they feel that it is appropriate.
Many attorneys will work with you regardless. Some may bill your hourly but put you on a payment plan. Others may bill you a retainer but forego payment until after the case has gone through. How the attorney will accept payment generally has nothing to do with how valid they believe that your case is; every attorney has their own rules for their financial agreements.