Medtronic's executives haven't mentioned that its $42.9 billion merger and relocation to Ireland to save on corporate taxes is actually going to generate a ton of other taxes here.

Why not say so? Perhaps because the company's not paying them. Its shareholders will be.

The tax bite coming for longtime Medtronic shareholders is just one more curious aspect of the Fridley-based company's combination with Covidien and establishment of its formal headquarters in Dublin.

Holders of the stock may not yet have figured it out, because didn't the news release Sunday say "acquire" in the headline?

Any seasoned investor knows that when a company in which he owns stock buys another, it's not taxable. No shares are being sold. No gain to be calculated. No taxes.

Not this time. When holders exchange their Medtronic stock for shares in an Ireland-based company the regulatory filings refer to as "New Medtronic," it's treated like a sale — a sale that will generate a tax but no cash proceeds that could be used to pay it.

Medtronic hasn't hidden this ­information, exactly, but all Chief Financial Officer Gary Ellis said on the Monday morning investor conference call was "it should also be noted" that the transaction will be a taxable event for federal income tax purposes for both Medtronic and Covidien shareholders.

OK. Duly noted.

If institutional investors cared more about these kinds of taxes, maybe Medtronic would, but they really don't. The shareholder of a mutual fund with a lot of Medtronic stock may not even realize, when she gets her 1099 tax notice from the fund company, that her tax bill seems kind of big.

Individuals who own the stock in a taxable account, on the other hand, will feel it. They will feel it like they would a kidney stone.

We are talking about long-term gains here, not selling at a profit after holding a stock less than a year. Long term means stock held not by traders but by investors, people who don't trade in part to keep taxes down.

Any gain from stock held long-term is taxed at a favorable federal rate of either 15 or 20 percent for most tax filers.

Andy Beuning, corporate tax director in the Twin Cities at the accounting firm Wipfli LLP, explained that a transaction taxable under federal law is typically taxable under state law. With the 3.8 percent federal net investment income tax on high earners to help fund the Affordable Care Act on top of state taxes, a Minnesotan could face up to a combined 30 percent tax rate on a 2014 sale.

The people who will pay the most are the people who owned the stock the longest, the very people who held on because they understood that Medtronic was one of America's great companies.

We know it today as a pillar of the Fortune 500, a company with $17 billion in revenue and about 49,000 employees, including more than 8,000 in Minnesota. But it's come a long way in 20 years.

Back then it employed just 8,700 people full-time worldwide, and revenue came to not quite $1.4 billion. Holders who saw the opportunity could have bought stock at a split-adjusted cost of less than $5 per share

With shares currently trading at just under $64 each, and if the deal closed at that price, a thousand-share holder at the highest tax bracket faces tax bills of more than $17,000.

The real old-timers who have held Medtronic stock for 30 years could have bought it at less than 50 cents per share, adjusted for splits. The taxable long-term gain for those folks will be all but equal to the price of the stock.

A handful of shareholders called and e-mailed this week, puzzled that the Star Tribune would describe an acquisition as taxable to them. Several then wanted to know whether Medtronic's executives had really thought it through.

Of course they did. A company spokesman said that management was "fully aware of the impact" and that by mentioning it now the company is "hopeful … that they have time to adequately think through and prepare how they might handle it."

Another sign of how well Medtronic's executives understood this deal is how they handled their own little tax problem.

Transactions like this one generate an excise tax at the capital-gains tax rate, call it 20 percent, on the value of stock compensation held by the directors and officers of the company. The reasoning here is that it should be painful to approve a so-called inversion transaction, when a U.S. company ends up abroad to save money in taxes.

It would've been painful too — had Medtronic not agreed to cover any liability for its insiders related to this excise tax.

The company, through a spokesman, explained that the board wanted to eliminate the potential that the insiders wouldn't support a transaction that was clearly going to benefit the shareholders long-term.

Of course, if the insiders were true believers, they could have taken a deep breath and paid the tax.

But with the big tax bite coming, longtime individual holders still are trying to sort through just how much of a benefit this deal will be.

The St. Paul investment adviser Mairs and Power manages accounts for individual clients alongside its funds, and some clients bought Medtronic stock decades ago.

In a conversation with portfolio manager Mark Henneman, he explained that one reason he and his colleagues have been reluctant to sell their clients' Medtronic stock is that they didn't want to stick them with a tax ­liability. Now they will have one anyway.

"It definitely disadvantages longtime shareholders who have been extraordinarily patient with this stock and this company," he said of the Covidien merger. "I don't get the sense that their interest got considered" in the transaction.

Henneman only then learned that the company will indemnify its insiders for the related excise tax.

"That's interesting," he said after a brief pause. He forgave me for breaking this news to him, saying "I was going to hear about it from someone."

Then he had to go. Perhaps he had some Medtronic stock to sell. • 612-673-4302