Morgan will win his 19th cap on Sunday, having come off the bench in England's last six internationals, including their three 2014 RBS 6 Nations matches.
Tom Johnson comes onto the bench to offer back row cover in the only other change made Lancaster to his matchday squad as England look to secure the Triple Crown.
"Ben has made an impact off the bench in the previous games. He has been pushing hard for the No 8 shirt and now gets his opportunity so we are looking forward to seeing him from the start," said Lancaster.
"Tom has been outstanding for Exeter Chiefs and gives us options off the bench as he has played in all three back row positions for his club."
Lancaster's two matches in charge against Wales have ended in defeat but his starting XV is much changed from that which was defeated 30-3 in Cardiff 12 months ago.
Only captain Chris Robshaw, fly-half Owen Farrell, loosehead prop Joe Marler and lock Joe Launchbury remain while Mike Brown and Tom Wood both featured in the Millennium Stadium in different positions.
Elsehwere, David Wilson continues to deputise for the injured Dan Cole at tighthead with Dylan Harley at hooker and Courtney Lawes continues at second row.
Danny Care and Farrell form the half-backs, Billy Twelvetrees and Luther Burrell are at centre and Jonny May and Jack Nowell continue on the wings.
"We can't wait to play at home again," added Lancaster. "The players have said that the atmosphere at Twickenham for the Ireland game was the best they had experienced and I am sure it will be the same again on Sunday.
"It definitely gives us an extra lift and that's what we want against another experienced, high quality side, who are looking to defend their title."
ENGLAND SIDE TO FACE WALES
15. Mike Brown (Harlequins)
14. Jack Nowell (Exeter Chiefs)
13. Luther Burrell (Northampton Saints)
12. Billy Twelvetrees (Gloucester)
11. Jonny May (Gloucester)
10. Owen Farrell (Saracens)
9. Danny Care (Harlequins)
1. Joe Marler (Harlequins)
2. Dylan Hartley (Northampton Saints)
3. David Wilson (Bath)
4. Joe Launchbury (London Wasps)
5. Courtney Lawes (Northampton Saints)
6. Tom Wood (Northampton Saints)
7. Chris Robshaw (Harlequins)
8. Ben Morgan (Gloucester)
16. Tom Youngs (Leicester Tigers)
17. Mako Vunipola (Saracens)
18. Henry Thomas (Sale Sharks)
19. Dave Attwood (Bath)
20. Tom Johnson (Exeter Chiefs)
21. Lee Dickson (Northampton Saints)
22. George Ford (Bath)
23. Alex Goode (Saracens)