Going from B cup to D cup with 415cc gummy bear implants. Is a breast lift warranted? Will I look fine without lift? (Photo)

Patient concerns regarding the appearance of their breasts can typically be divided in two pools: volume, ptosis (droop). The procedures to address these issues are as different as the issues themselves. However, these concerns are not mutually exclusive (some want smaller less droopy breasts and others want larger less droopy breasts).
There are two factors which can help to answer the question of which surgery will deliver the most satisfying result: mastopexy, augmentation or both. Patients must first consider the position of the NAC (nipple areolar complex i.e. the pigmented portion of the breast) as it relates to the inframammary crease. If the nipples are at or below the level of the crease the patient may benefit from a lift or mastopexy. The breast lift is designed to elevate sagging breasts to a more youthful position. It also helps to reshape and tighten the skin of the breasts. This is typically accomplished via a periareolar (around the nipple) incision with or without a vertical incision.
Mastopexy is an effective way to address sagging breast, however, the changes which accompany weight loss or pregnancy can also decrease volume of the breasts. When a woman wants the volume restored, or increased, a breast augmentation will also be needed in conjunction with mastopexy. Augmentation can help restore the volume loss which is well known to women following children. There are a number of options available to women considering augmentation ranging from size and implant type to access incision.   
A breast augmentation alone may be appropriate if ptosis is mild. If the patient is comfortable with the natural appearance of the breasts but desires them to be larger, a breast augmentation alone is the right procedure.  Augmenting significantly ptotic or sagging breasts tends to magnify the problem. In these cases, a mastopexy performed in conjunction with an augmentation is preferred.
Based upon your photos, you would likely obtain a very nice result from augmentation alone. Your NAC is well above your fold. The implant will not lift the breast, however, it does not appear that you would benefit from much of a lift.As always, discuss your concerns with a board certified plastic surgeon (ABPS).

You should be able to get a nice result without a beast lift. Although an implant does no lifting, it often gives the illusion of a lift.
Dr. Ted Eisenberg, Board Certified Plastic Surgeon and Author