You should aim for anything below words for an effective boilerplate. These basic pieces of information make up the core of a news story and get the facts across in a clear, concise way.
A good public relations manager usually writes the quotes and sends it to the concerned executives for approval. Because reporters are busy people, you must assume that they will only read the first sentence and then scan the rest -- and even that's a generous assumption.
Write short paragraphs—four lines maximum. It first states that Florida Blue will be expanding health care services for affected areas. Just tell them what your product, event, or service has to offer the reader.
Make it grammatically flawless. Remember, a product press release and a non-profit press release are going to look very different and require different approaches.
Even a single mistake can dissuade a reporter from taking you seriously. Provide access to more information. List real contacts up top. Lastly, it comes to the why. This will also force you to condense your most salient information into a more readable document -- something journalists are always looking for.
News is something new, up-to-the-minute and of interest to the readers.