Here is the current Masters Invitee list as of 3.29.15 as published by SB Nation.  At this time it's not necessarily everyone who has COMMITTED - with the big question mark being Tiger Woods.  There is also a chance that one more person could be in the field (making it an even 100) if the winner of the Shell Houston Open hasn't already qualified.  

To see how each of the players below qualified (Using Masters Primer 1 qualifications), please see the Invitee List on the official Masters web site here:  http://www.masters.com/en_US/players/invitees_2015.html

So how do you get into the Masters?  Well, according to www.masters.com here are the 19 ways a player can earn their invite to Augusta National:  

QUALIFICATION FOR INVITATION

1. Masters Tournament Champions (Lifetime)
2. US Open Champions (Honorary, non-competing after 5 years)
3. British Open Champions (Honorary, non-competing after 5 years)
4. PGA Champions (Honorary, non-competing after 5 years)
5. Winners of The Players Championship (Three years)
6. Current US Amateur Champion (6-A) (Honorary, non-competing after 1 year) and the runner-up (6-B) to the current US Amateur Champion
7. Current British Amateur Champion (Honorary, non-competing after 1 year)
8. Current Asia-Pacific Amateur Champion
9. Current Latin America Amateur Champion
10. Current US Amateur Public Links Champion
11. Current US Mid-Amateur Champion
12. The first 12 players, including ties, in the previous year's Masters Tournament
13. The first 4 players, including ties, in the previous year's US Open Championship
14. The first 4 players, including ties, in the previous year's British Open Championship
15. The first 4 players, including ties, in the previous year's PGA Championship
16. Winners of PGA Tour events that award a full-point allocation for the season-ending Tour Championship, from previous Masters to current Masters
17. Those qualifying for the previous year's season-ending Tour Championship
18. The 50 leaders on the Final Official World Golf Ranking for the previous calendar year
19. The 50 leaders on the Official World Golf Ranking published during the week prior to the current Masters Tournament