After last year's market correction, a growing number of investors are wanting to add more reliability to their stock portfolio. There are no guarantees of safety in the stock market, but there are certain stocks that can offer more consistency than others, particularly during times of volatility.

Income stocks like real estate investment trusts (REITs), for example, can be fantastic investments for reliability. Since these special types of real estate stocks are required to pay 90% of taxable income in the form of dividends, their income is one investors can rely on. It also adds diversification into new industries.

If you're looking to diversify and add some stability to your portfolio this year, here are three stocks fool.com contributors believe are worthy of considering.

1. American Tower: A safe bet in a high-demand industry

Liz Brumer-Smith (American Tower): American Tower (AMT -0.24%) is the second largest REIT by market capitalization and the world's largest communications infrastructure company. Size isn't always an indicator of reliability, but in the case of American Tower, which owns more than 225,000 communication assets around the globe, it certainly positions this company as the leading provider of a high-need service.

American Tower owns, develops, and leases communication assets such as cell phone towers and antennas to a wide range of communication companies, and this is a critical service in today's tech-driven society. In addition, the REIT owns a portfolio of data center facilities that help aggregate, store, and transmit data for an even larger pool of tenants, thus giving investors diversification into solutions that directly serve today's high-data needs.

Data usage is predicted to grow at a clip of 20% on a compounded annual basis by 2028. Plus, operators such as American Tower are also benefiting from the continued rollout of 5G technology domestically and internationally. The REIT has been facing some short-term headwinds as of late because of currency fluctuations and rapidly rising interest rates affecting its cost of borrowing. However, the company is still well positioned to maintain its attractive yield of nearly 3% and its 10 years of dividend increases.

AMT Dividend Chart

AMT Dividend data by YCharts.

Its dividend payout ratio of 67% means the company is more than capable of maintaining its dividends, even in a challenging macroeconomic climate. It has a stable debt ratio of 5.4 times its earnings before interest, taxes, depreciation, and amortization (EBITDA) and is actively working on reducing its floating-rate debt exposure to decrease the impacts of rising interest rates.

Since American Tower switched to a REIT in 2012, the company has outperformed the broader S&P 500, producing a 224% total return. With its healthy financial position and strategic position as a leading operator in a long-term-demand industry, I believe it's the ideal stock for diversification, income, and reliability right now.

2. Hannon Armstrong: A passive-income powerhouse that's making the world a better place

Kristi Waterworth (Hannon Armstrong Sustainable Infrastructure Capital): When the going gets tough, all you really want in your portfolio are stocks you can count on through good and bad times. For me, these are stocks that have not only paid a reliable dividend over the long term but also have a plan for their future that makes sense for our changing world.

Hannon Armstrong Sustainable Infrastructure Capital (HASI 0.89%) is easily one of my favorite future-looking stocks in the market. The infrastructure REIT not only has an absolutely fantastic mission, which is essentially to help finance a sustainable and green infrastructure for the world, but it's also a leader in this particular space, doing the hard work of regularly reviewing its business model and revising as necessary. There is no playbook to go by; the company ismwriting it as it goes.

This commitment to making its business all it can be, as well as its commitment to the environment, continues to deliver. For example, total interest income, its primary income source, was up 26% in 2022 over 2021, from $106.9 million to $134.7 million. Approximately 48% of its portfolio is made up of receivables, with only 9% being real estate leases for renewable-energy projects.

Its $4.3 billion portfolio includes "behind-the-meter" project funding, "grid-connected" funding, and sustainable infrastructure funding. This comes from a range of project types and project sources, including solar and wind, green real estate, public sector projects, and community and residential projects. It anticipates an additional closing of at least $750 million in funding from its current pipeline during 2023.

These long-term projects and plans are a great base for any investor looking for a reliable stock, but the other part of that equation is a reliable dividend, which Hannon Armstrong also provides. In the 10 years it's been paying a quarterly dividend, it's never been forced to reduce dividend payouts to investors. In fact, the company increased the quarterly dividend for Q1 2023 to $0.395 from Q4 2022's $0.375. As of the close of the market on March 14, its dividend yield is sitting at a lush 5.41%.

Hannon Armstrong Sustainable Infrastructure Capital is a company that's focused on the future of energy, as well as other sustainable practices that are vital for humanity. The capital it provides really makes a difference in the world, plus it pays a reliable dividend, which isn't anything to shake a stick at.

3. Agree Realty: Healthy payouts from a broad-based portfolio

Marc Rapport (Agree Realty): Owning shares of Agree Realty (ADC 0.29%) might be just as reliable as counting on your neighborhood supermarket to deliver the goods. In fact, this REIT may well own it. That's because grocery stores comprise about 9% of the rent coming in from the 1,839 properties that Agree currently owns across the country, and Kroger is its seventh largest tenant, at 2.9% of the rent roll.
https://filecache.investorroom.com/mr5ir_agreerealty/379/ADC%20Investor%20Presentation%20-%20January%20vF.pdf

Agree is a retail REIT with a long, diversified list of tenants, about 65% of them investment-grade companies. Walmart is its largest, at 6.9% of its rent, and Agree operates in nearly every state, adding geographic diversity as well.

This suburban Detroit operation was already an accomplished shopping-center developer when it went public in 1994 and since that time has churned out an annualized total return of 12.5%, doubling that of the S&P 500.

ADC Total Return Level Chart

ADC Total Return Level data by YCharts.

Agree also is a reliable provider of passive income, growing its dividend by an average of 6.1% a year in the past decade, including four payout bumps just since Agree began paying monthly dividends in January 2021.

Agree has been good to investors, and the market has been good to Agree even in these rough times. Shares are selling for about $70, up about 8% from this point last year, and they provide a nice yield of about 4.1%. Analysts, meanwhile, give it a consensus target price of $78.23, seeing even more upside to this proven, reliable dividend stock.