Bamford had a temporary stint at stadium:mk in December but the 19-year-old striker's stay was cut short by injury on Boxing Day in only his second appearance for the League One club.
"I am delighted to have Patrick back until the end of the season, he made a really big impression on the football club in his short time here and I hope he can make a telling impact over the next few months," said Dons boss Karl Robinson.
"He is a talented footballer who adds great strength in depth to our attacking options and that was our aim in this transfer window.
"He is currently completing his rehab work with Chelsea but we had to act in order to keep him for the remainder of the season, and we hope he will be with us in the next two weeks."
