\documentstyle[11pt]{letter}
\renewcommand{\textwidth}{5.75in}

\begin{document}

\begin{letter}{Health Americ of Pittsburgh\\
		Att: HMO Claims\\
		PO Box 2625\\
		Pittsburgh, PA\ \ 15230}

\address{Todd W.\ Mummert\\
		416 Earlwood Road\\
		Pittsburgh, PA \ \ 15235}

\opening{To whom it may concern:}

I'm enclosing yet another bill that was sent to my address, since the
hospital apparently doesn't have your address on file.  I supposedly
now have a referral number (re: phone conversation w/ member
services.  I believe you have already paid on at least two bills
regarding this incident in November.  It seems every department/group
is billing me separately.  I believe this one has been sent at
least once before to you.

\closing{With thanks,}
\signature{Todd W.\ Mummert}
\end{letter}
\end{document}