Letters of recommendation are an important factor in the medical school admissions process. We do not provide committee (composite) letters at Berkeley.
AMCAS has also developed Letters of Evaluation Guidelines to help you and your letter writer strategize the organization of the letter and the key competencies to convey in the letter.
To ensure that all of your letters of recommendation have arrived, make sure you open an account with Interfolio, for your letter writers to upload their letters to.