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The primary concern of many dividend-focused investors is to find stocks that offer up a high yield. While I appreciate a big payout as much as anyone else, it's a big mistake to judge income-producing stocks solely by their yields. After all, a big dividend yield is one way the market signals to investors that a company has poor growth prospects, which hints that the company might have a hard time increasing its payout in the future.

For that reason, I prefer to purchase companies that can easily afford to raise their payout in the future. Below are three high-quality healthcare stocks that stand a good chance of boosting their dividends in future years. Read on to see if any of them deserve a place in your portfolio.

A biotech blue chip

Over the past three decades Amgen (AMGN -0.37%) has grown into one of the biggest and most important healthcare companies in the world. Thanks to the blockbuster success of best-selling drugs like Neupogen, Epogen, and Enbrel, Amgen has turned into a true financial powerhouse.

In 2011 Amgen decided to turn itself into an income stock by turning on its dividend spigot. The company started by paying a modest quarterly payment of $0.28 per share, but it has been raising its payout like clockwork ever since.

Image source: Amgen.

Last December Amgen announced that it would raise its dividend again, and this time by a hefty 27%. All of those dividend bumps add up, and the company now pays a quarterly dividend of $1 per share. That's big enough to give it a market-beating dividend yield of 2.73%.

However, even after this big boost, the dividend only consumes about 40% of Amgen's earnings. That gives the company plenty of room to continue raising its dividend payment at above-average rates in future years.

That's especially true when you consider that Amgen is still firmly in growth mode. Nine of its drugs posted double-digit sales growth last quarter, which was good enough to push the company's top line up a strong 10% overall.

Still, Amgen does face some challenges in the years ahead, most importantly from biosimilar competition for its legacy products. However, the company has a plan to overcome that threat: It has built out its own pipeline of biosimilar drug candidates. Combine that with its slew of other drugs that are still growing fast, and the company should be able to grow its bottom line -- and its dividend -- for years to come.

A medical-device top dog

Each day, roughly 10,000 baby boomers reach retirement age. Amazingly, that trend is expected to continue for at least 13 more years, which should greatly increase future demand for medical devices.

Image source: Pixabay user Huskyherz.

That trend should greatly benefit Medtronic (MDT -0.57%), one of the largest medical-device companies on the planet. Medtronic's product portfolio spans the healthcare system, and it holds a strong competitive position in a diverse set of disease states. Altogether its products pulled in more than $28 billion in total revenue last year.

The company hasn't been shy about using its financial strength to round out its product offerings. The company recently purchased the gynecology business of Smith & Nephew, which will give it a chance to expand its presence in the field of minimally invasive surgery. Last month it signed an agreement with Mazor Robotics that will allow it to co-promote the company's innovative Renaissance robotic surgery guidance system. With these deals added to the company's core lineup of products, it's easy to believe that this company has a bright future.

Even with these investments, Medtronic still has has plenty of excess capital lying around to reward shareholders. The company just announced a 13% increase in its quarterly dividend payout, which gives it a new annual dividend payment of $1.72 per share. That marks the 39th consecutive year that the company has bumped its payout, which makes Medtronic a member of the exclusive S&P 500 Dividend Aristocrats. Shares are currently yielding just under 2%, and since the dividend only consumes about 40% of the company's earnings, I think investors can expect more of the same for years to come.

An Amazon-proof retail giant

Pharmacy retail giant CVS Health (CVS -1.42%) also exhibits many of the traits that make for an attractive income stock. The company's dominant industry position gives it a wide economic moat -- so wide, in fact, that I'm on record as calling the business Amazon-proof.

CVS Health is divided into two main business units: a pharmacy benefit management (PBM) business and a retail empire.

The company's PBM business helps employers, unions, and governments rein in their spending on pharmaceuticals. CVS Health can do so because it has decades of experience in the business and enormous buying power. That allows it to negotiate favorable prices with drugmakers, which it then passes on to its customers.

Image source: CVS Health.

CVS Health's retail stores enjoy an enviable position as the market-share leader in the U.S. The company is also pushing hard to extend its lead by making its services even easier to access. A good example of that is last year's $1.9 billion acquisition of Target's pharmacy and clinic business, which brings the company one step closer to meeting its customers at a convenient location. Add in the fact that CVS offers easy access to basic medical care at its in-store Minute Clinics, and I think customers will stay very loyal to the company's brand. That's a big reason why I think that CVS Health is a stock that even Warren Buffett could learn to love.

CVS Health's wide moat puts it in a great position to treat its shareholders well. The company has paid an ever-growing dividend for more than 30 years now, and with revenue and profits heading in the right direction, I expect that trend to continue.

Last year the company increased its dividend by 21%, and it's currently yielding about 1.8%. Despite the recent double-digit raise, the company's payout ratio is only 32%, which is still a bit below its long-term target of 35%. That implies that investors should have no problem with dividends falling in the years ahead, especially since earnings are expected to grow by double digits.