We've seen some unclear reports as to when Peyton Manning's neck examination must occur by, but Jeff Legwold has more of the details. Per Legwold, the annual exam must take place at least 10 days before the new league year starts, at 4pm ET on March 10.
That 10-day stipulation would actually appear to place the exam deadline on February 28 (Legwold says it's March 1), but if Chris Mortensen is correct (as he usually is in matters relating to Manning, as both are represented by CAA), Peyton figures to announce his return long before then.
Manning's $19M salary for 2015 becomes fully guaranteed on March 9, a day before the league year kicks off.
Just to cover all of the possibilities, he could pass his neck exam, but still retire or be cut by Denver prior to March 9, and be owed nothing. This is different from his 2013 neck exam, the passage of which converted his 2013 and 2014 salaries to being fully guaranteed.
We haven't seen it reported expressly, but it's our assumption that the final year of Manning's contract, in 2016, is structured very similarly, if not exactly the same.