Five Democratic senators are demanding that Aetna explain how its abruptdecision to leave multiple Affordable Care Act exchanges, afterpreviously declaring its intent to expand its presence, can bejustified — other than by the U.S. Department of Justice’schallenge to its proposed merger with Humana.

The Huffington Post reports a letter sent to BillBertolini, Aetna’s chief executive officer, from Sens. BernieSanders of Vermont, Elizabeth Warren of Masschusetts, Ed Markey ofMassachusetts, Sherrod Brown of Ohio and Bill Nelson of Florida,calls for an explanation by Sept. 15 for the company’s sudden turnagainst exchanges.

Of particular interest to the senators is the fact that Aetna warned in a letter priorto the Justice Department’s position on the merger that it wouldback off from its commitment to the ACA exchanges if its mergerwere blocked.

Prior to the Justice Department's action regarding the proposedHumana merger, Aetna had saidthat its presence on 15 exchanges was sufficiently successful thatit actually planned to increase its participation and expand intoadditional markets. It also represented its presence on theexchanges as a positive factor for its business, even in investorcalls, and never characterized the merger as critical to itsability to remain on the exchanges.

Once the Justice Department voiced its objection to the merger,however, Aetna instead announced its intent to withdraw from 11 ofthose 15 markets in which it participated, rather than expanding to20 as it had previously intended.

The about-face, the senators say, is all the more remarkable notonly because of the company’s previous bullish stance on theexchanges but also because of provisions of the proposed merger,and indeed the merger itself — now depicted as crucial to thecompany’s continuing presence in the exchanges.

The senators wrote, “We are particularly troubled that Aetna’sdecision to leave the ACA exchanges appears to have been motivatedby the Justice Department’s decision to challenge Aetna’s proposed$37 billion merger with Humana — a deal that the Justice Departmentand many experts predicted would harm competition in the healthinsurance market and negatively impact the cost and quality ofhealth care. Aetna could not have been surprised at the concernsraised by regulators about this merger.”

In July, Bertolini wrote to the Justice Department: “[I]f thedeal were challenged and/or blocked we would need to take immediateactions to mitigate public exchange and ACA small group losses.Specifically, if the DOJ sues to enjoin the transaction, we willimmediately take action to reduce our 2017 exchange footprint …[I]nstead of expanding to 20 states next year, we would reduce ourpresence to no more than 10 states … [I]t is very likely that wewould need to leave the public exchange business entirely and planfor additional business efficiencies should our deal ultimately beblocked.”

The senators characterize Bertolini’s letter to the JusticeDepartment as “an effort to pressure the Justice Department intoapproving a merger that the department has alleged violatesantitrust law and has the potential to significantly harm consumersall across the country.” The senators’ letter includes a list ofquestions for Bertolini to answer by Sept. 15.

In a response to the Huffington Post report about the senators’letter, Aetna spokesman T.J. Crawford was quoted saying in part,“Singling Aetna out may be politically convenient during electionseason, but this letter ignores realities and takes the focus awayfrom needed reforms.”