For William Roper, CEO of the UNC Health Care System, the mega-merger of Express Scripts and Medco Health Solutions announced this morning could mean a $3 million payday.

Roper, who has been a Medco board member for nearly four years, will receive cash and Express Scripts stock worth as much as $3 million for Medco shares and options he owns.

But he also may lose his Medco board seat. That's a job that paid him total compensation worth $272,789 last year, according to a Securities and Exchange Commission filing.

Two "independent" Medco directors will join an expanded Express Scripts board when the deal closes, but the companies haven't picked them, said Medco spokesman Lowell Weiner. Medco listed eight independent directors in an April SEC filing, including Roper.

Roper has faced criticism over his board work, and whether UNC Health does enough to disclose potential conflicts of interest and his compensation.