Good news from a company should be good for its stock, right? That makes sense. However, it doesn't always work out that way in the real world.

UnitedHealth Group (UNH 1.35%) serves as a great example. The giant health insurer reported its first-quarter results before the market opened on Friday. The news was good across the board. Yet shares fell rather than moving higher. 

Sometimes, though, such declines create opportunities for investors. Is UnitedHealth Group stock a buy on the dip?

Looking up

Everything -- and I mean everything -- looked good in UnitedHealth Group's Q1 update. The company reported revenue of $91.9 billion. That reflected a solid year-over-year increase of 15%. It was also well above Wall Street's consensus revenue estimate of $89.8 billion.

UnitedHealth Group's health insurance segment performed well in Q1 with revenue jumping 13% year over year to $70.5 billion. Its Optum health services segment delivered even stronger growth with revenue soaring 25% to $54.1 billion. (By the way, the sum of these two amounts is less than the company's total reported revenue because of intersegment eliminations.)

The company posted Q1 earnings of $5.95 per share based on generally accepted accounting principles (GAAP), up nearly 13% year over year. Its non-GAAP (adjusted) earnings totaled $6.26 per share. This reflected a 14% increase over the prior-year period amount and blew past the average analysts' earnings estimate of $6.13 per share.

UnitedHealth Group even raised its full-year guidance. The company now expects GAAP net earnings of between $23.25 and $23.75 per share. Adjusted net earnings are projected to be between $24.50 and $25 per share. 

Heading down

Those are the kind of numbers that should cause investors to smile. So why did shares of UnitedHealth Group slide as much as 3.4% lower on Friday?

You can't blame it on the overall market. Sure, the major market indexes were down. However, none of them dropped all that much. The S&P 500 slipped only around 0.3% lower.

Perhaps the best guess as to why UnitedHealth Group stock fell is that the company's guidance raise wasn't as much as some hoped it would be. Keep in mind that the health insurer ranks as one of the best-performing stocks in the Dow Jones Industrial Average in recent weeks. Investors were already banking on a strong Q1 performance.

While UnitedHealth Group boosted its full-year guidance, it wasn't really anything to get excited about. The company's previous outlook was for adjusted net earnings in 2023 of between $24.40 and $24.90 per share. After an exceptional Q1 performance, UnitedHealth only increased the midpoint of its full-year guidance by $0.10 per share.  

Buy on the dip?

There are reasons to be optimistic about UnitedHealth Group's future. The company recently won Medicare contracts in Indiana and Texas. The revenue backlog for its Optum Insight business stands at $30.7 billion, 35% higher than it was a year ago.

UnitedHealth's Medicare Advantage business continues to perform really well. I expect this momentum will continue as more Americans retire and as more current retirees switch from traditional Medicare to Medicare Advantage plans.

However, UnitedHealth Group stock isn't cheap. Shares trade at nearly 21 times expected earnings. That's well above the forward earning multiples for the S&P 500 and the average for managed healthcare companies.

Also, the U.S. Congress could go after pharmacy benefits managers (PBMs). UnitedHealth Group's OptumRx ranks as one of the biggest PBMs in the country.

On the other hand, if the U.S. enters a recession, investors could turn to the stock as a safe haven. And the Federal Reserve appears to think that a mild recession is now more likely this year because of the banking crisis.

Overall, I think that the pros for UnitedHealth Group outweigh the cons. My view is that investors should consider buying the stock on the recent dip.