Aetna ( AET), one of TheStreet Ratings' top-rated managed health care stocks, is the third-largest managed care organization in the country, providing health care benefits for more than 35 million Americans. That size gives Aetna the ability to heft its weight around when negotiating with healthcare providers, a necessary bit of leverage in an increasingly cost-conscious industry. A recently activated provision of the recent health care reform legislation means that insurers are now required to pay out a minimum portion of premiums on subscriber care. While the move doesn't impact Aetna as much as some other peers, it certainly puts added pressure on operating efficiency for the healthcare industry. Like most insurers, Aetna has a large benefits-plan-management business where the company collects fees in exchange for administering companies' own insurance programs. That business could become increasingly important for Aetna, particularly as legislation and market risk to the firm's massive portfolio weigh on investors. Aetna's scale makes the firm one of the best candidates to embrace the fee-based business more fully. Last Friday, Aetna increased its quarterly dividend by 16.67%, a move that ratchets the firm's payout to 17 cents per share. That's a 1.74% yield at current price levels.