It's not often that you get a Christmas gift from Uncle Sam. Now that a $600 stimulus check could be on the way, it's a great time to pick a few stalwart stocks to shore up your portfolio's long-term value. Of course, that's assuming all your bills have been covered and your emergency fund is secure. In my view, companies that have strongly recurring revenue tend to be safe investments. But safer still are companies that have a track record for revenue-bearing innovation that allows them to consistently grow over time. Image source: Getty Images. 1. Pfizer Pfizer (NYSE: PFE) has been in the headlines lately thanks to its recently approved coronavirus vaccine, but it's also a stable pharma giant. Even before its vaccine, the company's roster of crucial medicines made it a powerhouse, netting it $48.65 billion in revenue over the last 12 months. The need for its products like the analgesic Lyrica (for pain) or Lipitor (for heart disease) won't be going away anytime soon, and it's always working hard to develop the next blockbuster drug. In its late-stage clinical pipeline alone, Pfizer has 21 different projects, plus six others that are on the verge of hitting the market if they get the final go-ahead from regulators. Potential investors should also be pleased to know that it recently spun off Upjohn, its perennially underperforming generic drug division. Upjohn combined with another generic drug manufacturing company, Mylan, to form a new entity called Viatris (NASDAQ: VTRS). Now that this transaction is done, Pfizer's management anticipates revenue growth of around 6% per year through 2025. Given the probable impact of worldwide coronavirus vaccine sales, it's hard to see how Pfizer could miss in the new year. 2. Abbott Labs When it comes to evergreen healthcare stocks, Abbott Laboratories (NYSE: ABT) is one of the leaders. You'll find many sources of recurring revenue in its product lineup and consumer-facing line of healthcare goods, which includes brands like Pedialyte. More importantly, Abbott is a major innovator and supplier of diagnostic tests, surgical tools, and other products that healthcare facilities simply can't do without, so a large portion of its income is safe from disruption. Per the Q3 earnings report, its diagnostics segment grew by 38.8% thanks to the demand for coronavirus tests, of which it has sold more than 100 million units so far this year. Abbott hasn't had any trouble growing its earnings over time, even in highly challenging market conditions. Its free cash flow has more than doubled in the last four years. Add to that the fact that management has increased dividend payouts for the last 49 years in a row, and investors should have plenty of confidence that the company's edge isn't disappearing. 3. Costco Costco Wholesale (NASDAQ: COST) is the world's third-largest retailer. It's an exceedingly safe company because it has spent decades operating comfortably despite a consistently narrow profit margin, growing revenue all the while. As consumers and businesses rely on it for everything from groceries to T-shirts, their purchasing patterns are deeply predictable, which protects the bottom line and supports sales growth over time. Because the company charges a membership fee each year, it also has significant and strong recurring revenue; more than 90% of its members renew their subscription each year. Last quarter, these membership fees totaled $861 million, and Costco didn't need to sell a thing to earn them. The pandemic hasn't harmed Costco's margins, and its sales grew by 17% year over year in the most recent quarter. What's more, the types of products that people buy from the company aren't about to get cut when a customer's disposable income drops. If anything, Costco's low prices and wide range of products make it the go-to retailer for cash-strapped consumers. Plus, a strong return policy means that people aren't afraid to make big purchases with the company. 10 stocks we like better than PfizerWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Pfizer wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of November 20, 2020 Alex Carchidi owns shares of Abbott Laboratories. The Motley Fool owns shares of and recommends Costco Wholesale. The Motley Fool has a disclosure policy.Source