Each business day, TheStreet.com Ratings TheStreet.com Ratings compiles a list of the top five stocks in one of five categories -- fast-growth, all-around value, large-cap, mid-cap and small-cap -- based on data from the close of the previous trading session. Today we focus on mid-caps. These are stocks of companies that have market capitalizations of between $500 million and $10 billion that rank near the top of all stocks rated by our proprietary quantitative model, which looks at more than 60 factors.The stocks must also be followed by at least one financial analyst who posts estimates on the Institutional Brokers' Estimate System. They are ordered by their potential to appreciate. Note that no provision is made for off-balance-sheet assets such as unrealized appreciation/depreciation of investments, market value of real estate or contingent liabilities that might affect book value. This could be material for some companies with large underfunded pension plans. HMS Holdings ( HMSY) provides a variety of cost containment and payment accuracy services relating to government healthcare programs. We have rated this stock a buy since September 2004 on the basis of such strengths as the company's largely solid financial position, good cash flow from operations, and growth in revenue, net income, and earnings per share. For the fourth quarter of fiscal 2008, the company reported that its earnings surged 74.9% on higher revenue. Net income rose from $4 million in the fourth quarter of fiscal 2007 to $7.1 million in the most recent quarter. Revenue increased 25.8% year over year, greatly exceeding the industry average of 7%. This increase, led by strong revenue growth in each of the government healthcare program markets, appears to have helped boost EPS, which showed significant improvement over the same quarter a year ago, rising from 15 cents to 26 cents per share. HMS Holdings has a very low debt-to-equity ratio of 0.1, which implies that it has successfully managed its debt levels. In addition, a quick ratio of 3.2 clearly demonstrates an ability to cover short-term cash needs. Finally, net operating cash flow increased 17.5% when compared to the same quarter of last year.