AT&T Inc. is starting to make good on its promise to tackle its $171 billion debt load.

The telecom carrier is refinancing outstanding debt by selling senior unsecured bonds in as many as two parts, according to a filing Wednesday. The largest nonfinancial issuer of corporate debt, AT&T has made debt reduction its “top priority” for this year. The proceeds of Wednesday’s sale, along with cash on hand, will go toward repaying some bonds issued by AT&T as well as subsidiaries of DirecTV, which AT&T bought in 2015 for $49 billion.

Through its acquisition of DirecTV, and more recently its blockbuster buy of Time Warner Inc. for $85 billion last year, AT&T amassed a debt load as high as $180 billion. Though the company pledged to pay down debt with each deal, credit raters have expressed concern about the amount of debt relative to its earnings, a metric known as leverage. AT&T is rated two steps above speculative grade with a stable outlook by Moody’s Investors Service and S&P Global Ratings.

A representative for AT&T didn’t immediately respond to a request for comment.

That rating, squarely in the middle of the BBB rankings, is the lowest tier of investment-grade, where now half of the $5 trillion market resides. Many companies like Verizon Communications Inc. and Anheuser-Busch InBev NV have ended up there as well, also through by taking advantage of decade-long low interest rates to finance acquisitions at the expense of credit metrics.

This time around, they’re coming back to the capital markets for a different reason. AB InBev borrowed $15.5 billion last month in the year’s largest bond sale so far to refinance some of the debt it took on to buy SABMiller Plc in 2016. Verizon, which has been actively addressing its balance sheet since buying Vodafone Plc’s stake in Verizon Wireless in 2014, is in the process of exchanging upcoming bonds for $4 billion of new notes with longer maturities.

It all adds up to make 2019 the year of the “debt diet,” Peter Tchir, head of macro strategy at Academy Securities, said on Bloomberg TV this week.

“This is really a year that corporations are going to focus on their debt, and they’re going to remain conscious about how much debt they take on,” Tchir said. “We’re going to see companies focus on their balance sheet, and that will actually be good for stock prices. And that’s why they’re doing it.”

AT&T, like Verizon, is trying to address its near-term maturities in 2020 and 2021 with Wednesday’s bond sale, according to the filing. The longest portion of the two-part offering, a 20-year security, will yield 2.2 percentage points above Treasuries, after initially discussing around 2.375 percentage points, said a person with knowledge of the matter, who asked not to be identified as the details are private.

Dallas-based AT&T has said it plans to pay down about $20 billion of debt this year through a combination of internally-generated free cash flow and asset sales. Given the company’s expectation to generate about $12 billion of cash after dividends, it’s unlikely AT&T will approach the debt markets again this year for refinancing purposes, Bloomberg Intelligence analyst Stephen Flynn said on Bloomberg Radio Wednesday.

BNP Paribas SA, Goldman Sachs Group Inc., Morgan Stanley and Wells Fargo & Co. are managing the bond sale, according to the filing.