Your approach to picking stocks is pretty simple if you're in your 70s. There are three basic rules.

The first two rules are the same as Warren Buffett's two rules of investing:

  • Rule No. 1: Never lose money.
  • Rule No. 2: Don't forget rule No. 1.

Investors in their 70s will probably want to add rule No. 3: Receive a dependable income from dividends.

Your best way to abide by all three of these rules is to find stocks with solid business models built for the long run that pay out steady dividends. Three stocks that I think meet those criteria are Iron Mountain (NYSE:IRM), Welltower (NYSE:WELL), and Pfizer (NYSE:PFE). Here's why you should consider buying these three stocks if you're in your 70s.

Couple in their 70s pouring orange juice

Image source: Getty Images.

1. Iron Mountain

Iron Mountain's business model is as solid as its name. The company is by far the biggest provider of records and data storage in the world. If you threw a dart at a list of the 1,000 largest companies, there's a really good chance you'll land on one of Iron Mountain's customers. Its customer base includes 95% of the Fortune 1000. 

The company's core business is growing. Customers tend to stay with Iron Mountain in large part because of the hassle of moving records and data somewhere else. And they continue to generate more records and data that require off-site storage.

Iron Mountain is looking to grow in other ways, too. It's expanding in emerging markets. The company is also moving into adjacent businesses such as fine arts storage. Iron Mountain's biggest initiative to fuel more growth is its expansion into operating data centers.

I view the stock as a dividend investor's dream. Iron Mountain's dividend currently yields 6.71%. The company thinks it will be able to increase the dividend by at least 4% in the coming years. Over the last three years, Iron Mountain exceeded that goal, boosting its dividend by a total of 24%.

2. Welltower

Welltower ranks as the largest healthcare real-estate investment trust (REIT) and the fifth-largest REIT across all sectors. The company owns nearly 1,300 properties in the U.S., Canada, and the United Kingdom and leases these properties to healthcare providers.

Around 72% of Welltower's properties provide senior housing, including independent living, assisted living, and memory care. Another 11% of the company's properties are skilled nursing facilities. The remaining 17% of Welltower's properties are outpatient medical clinics.

The company's primary area of focus should especially enjoy strong growth over the long run. Annual increased demand for senior housing units is projected to quadruple by 2030. Welltower should also see nice growth for its outpatient medical properties business as healthcare providers continue to transition care to lower-cost settings.

Welltower's dividend yield of 6.45% looks attractive, especially in light of the company's growth prospects. Although the company has only provided small dividend hikes in recent years, I doubt many investors will complain about Welltower's yield.

3. Pfizer

Pfizer is the biggest drugmaker in the world. Although Johnson & Johnson claims a higher market cap, much of the healthcare giant's revenue stems from consumer health products and medical devices. Pfizer is also one of the oldest pharmaceuticals companies, with its roots dating back to 1849. 

The company is well known for its prescription drugs such as blood thinner Eliquis, breast cancer drug Ibrance, and immunology drug Xeljanz. Pfizer also markets popular consumer healthcare products including Advil, Centrum, and Robitussin.

Like other drugmakers, Pfizer's future growth depends on its pipeline. The company currently claims 28 drugs in late-stage clinical development. Pfizer thinks that over the next five years, it will be able to win approval for up to 15 new drugs or new indications for existing drugs that have blockbuster sales potential -- a much higher number than the company has achieved in recent years.

Pfizer's dividend currently yields 3.73%, which ranks as one of the best yields among big pharma companies. The company has increased its dividend by more than 21% over the last three years. Even better, Pfizer appears to be in great shape to keep the dividends -- and dividend hikes -- coming.

One thing to note

There's one thing that you should note about the first investing rule. The goal of never losing money applies to the long run. Any of these three stocks (or any other stock, for that matter) can go down in the short term. However, Iron Mountain, Welltower, and Pfizer have the solid business models that have made them successful in the past and should continue to do so long into the future. 

Keith Speights owns shares of Pfizer. The Motley Fool owns shares of Johnson & Johnson. The Motley Fool has a disclosure policy.