Inclusion Criteria:

          -  Pathologically confirmed residual invasive breast cancer, in the breast and/or lymph
             node(s), following neoadjuvant chemotherapy. In the absence of residual invasive
             disease in the breast, lymph node must contain at least 2mm of invasive disease.

          -  HER2 negative by local pathology assessed according to current ASCO/CAP guidelines:

               -  In situ hybridization non-amplified (ratio of HER2 to CEP17 < 2.0 or single probe
                  average HER2 gene copy number < 4 signals/cell), OR

               -  Immunohistochemistry (IHC) 0 or IHC 1+.

               -  NOTE: If more than one test result is available and not all results meet the
                  inclusion criterion definition, all results should be discussed with the
                  Principal Investigator to establish eligibility

          -  ER and PR negative defined as < 10% of cells expressing hormonal receptors via IHC
             analysis by local laboratory assessment.

          -  Patients must have received neoadjuvant chemotherapy prior to breast surgery.

          -  Patients must be within 12 months of last therapy (definitive breast surgery,
             radiation and/or all intended adjuvant therapy). Definitive breast surgery includes
             lumpectomy or mastectomy with pathologically clear margins (i.e. no ink on tumor). For
             patients undergoing lumpectomy, this must be followed by whole breast irradiation.
             Definitive surgery also includes axillary surgery, either sentinel lymph node biopsy
             or axillary lymph node dissection at the discretion of the attending surgeon.

          -  Evidence of circulating tumor cfDNA in blood sample collected after completion of all
             local and systemic neoadjuvant and adjuvant therapy (preoperative and postoperative
             chemotherapy, surgery and radiation), confirmed by central testing. Detection of any
             tumor specific mutations (TSMs) within the sample will be considered positive for
             purposes of study eligibility.

          -  Concurrent receipt of bone modifying agents (bisphosphonates or rank-ligand
             inhibitors)is allowed.

          -  Prior treatment with an immune checkpoint inhibitor in the neoadjuvant or adjuvant
             setting is permitted.

          -  ECOG Performance Status of 0 or 1

          -  Men and women, age ≥ 18 years

          -  Adequate hematologic and organ function defined by the following:

               -  ANC ≥ 1.5 × 109/L (1500/μL) without granulocyte colony-stimulating factor support

               -  WBC count ≥ 2.5 × 109/L (2500/μL)

               -  Absolute Lymphocyte count ≥ 0.5 × 109/L (500/μL)

               -  Platelet count ≥ 100 × 109/L (100,000/μL)

               -  Hemoglobin ≥ 90 g/L (9.0 g/dL), with or without transfusion

               -  AST, ALT, and alkaline phosphatase (ALP) ≤ 2.5 × institutional upper limit of
                  normal (ULN).

               -  Serum bilirubin ≤ 1.5 × institutional ULN with the following exception:

                    -  Patients with known Gilbert syndrome: serum bilirubin level ≤ 3 ×
                       institutional ULN

               -  Serum creatinine < 1.5 x institutional ULN

               -  Serum albumin ≥ 25 g/L (2.5 g/dL)

               -  Fasting glucose < 150 mg/dL and hemoglobin (HBA1c) < 7.5%

               -  For patients not receiving therapeutic anticoagulation: INR or aPTT ≤ 1.5 ×
                  institutional ULN

               -  For patients receiving therapeutic anticoagulation: stable anticoagulant regimen

          -  Women of childbearing potential (pre-menopausal) must have a negative serum or urine
             pregnancy test within 7 days prior to start of therapy. A woman is defined as
             premenopausal if she is less than 12 months from last menstrual period with no
             identified cause other than menopause (medication induced amenorrhea is not
             acceptable). Pregnancy test is not required in women who are surgically sterile via
             bilateral salpingooophorectomy or hysterectomy.

          -  Women of childbearing potential and men must agree to use adequate contraception for
             the duration of protocol treatment and for 28 days after last dose of ipatasertib and
             5 months after stopping atezolizumab. Hormonal contraceptives are not acceptable (see
             section 5.6).

          -  Ability to understand and the willingness to sign a written informed consent document.
             Non-english speakers are eligible to participate but will be excluded from
             surveys/questionnaires unless the participant has a proxy available for translation.

        Exclusion Criteria:

          -  Clinical evidence of metastatic disease

          -  Residual DCIS or LCIS alone without invasive cancer OR pT0N0i and pT0N1mic residual
             disease

          -  Concurrent enrollment on another investigational therapy trial

          -  Prior treatment-related toxicity must be resolved to ≤ Grade 1 with the exception of
             alopecia and peripheral neuropathy, prior to study enrollment.

          -  Major surgical procedure, other than for diagnosis, within 4 weeks prior to initiation
             of study treatment, or anticipation of need for a major surgical procedure during the
             study

          -  Treatment with therapeutic oral or IV antibiotics within 2 weeks prior to initiation
             of study treatment Patients receiving prophylactic antibiotics (e.g., to prevent a
             urinary tract infection or chronic obstructive pulmonary disease exacerbation) are
             eligible for the study.

          -  Intercurrent illness including, but not limited to: ongoing or active infection
             requiring systemic therapy, active tuberculosis, serious liver disease such as
             cirrhosis, active bleeding diathesis, uncontrolled Type I or Type II diabetes
             mellitus, Grade ≥ 2 uncontrolled or untreated hypercholesterolemia,
             Hypertriglyceridemia or hypercalcemia

          -  Cardiovascular disease including: congestive heart failure of New York Heart
             Association Class III or IV, myocardial infarction (<6 months prior to enrollment)
             unstable angina pectoris, serious uncontrolled cardiac arrhythmia or any other
             clinically significant cardiac disease, in the opinion of the investigator

          -  History of idiopathic pulmonary fibrosis, organizing pneumonia (e.g., bronchiolitis
             obliterans), drug-induced pneumonitis, or idiopathic pneumonitis, or evidence of
             active pneumonitis on screening chest computed tomography scan. History of radiation
             pneumonitis in the radiation field (fibrosis) is permitted.

          -  Active (acute or chronic) autoimmune disease of any type except hypothyroidism on a
             thyroid-replacement hormone,or celiac disease, or well-controlled psoriasis, eczema,
             lichen simplex chronicus or vitiligo.

          -  Impairment of gastrointestinal function or active gastrointestinal disease that may
             significantly alter the absorption of the study agents (e.g., ulcerative disease,
             uncontrolled nausea(> grade 2), vomiting (> grade 2), diarrhea (> grade 2),
             malabsorption syndrome or small bowel resection).

          -  Congenital long QT syndrome or screening QT interval corrected through use of
             Fridericia's formula >480 ms.

          -  Participants known to be positive for the human immunodeficiency virus (HIV),
             Hepatitis B antigen (HepBsAg), or Hepatitis C virus (HCV) RNA are ineligible.

          -  History of prior invasive breast cancer in either breast.

          -  Participants with history of prior malignancy other than breast cancer are eligible if
             they have been disease-free for at least 5 years prior to enrollment with the
             exception of patients with thyroid cancer that has been definitively treated without
             spread to regional lymph nodes.

          -  Treatment with strong CYP3A4 inducers within 4 weeks or 5 drug-elimination half-lives,
             whichever is longer, prior to initiation of study drug.

          -  Treatment with a live, attenuated vaccine within 4 weeks prior to initiation of study
             treatment, or anticipation of need for such a vaccine while on protocol treatment

          -  Known allergy or hypersensitivity to any of the study drugs or any of their
             excipients, including chimeric or humanized antibodies or fusion proteins and Chinese
             hamster ovary cell products or recombinant human antibodies

          -  Treatment with systemic immunosuppressive medication (including, but not limited to,
             corticosteroids, cyclophosphamide, azathioprine, methotrexate, thalidomide, and
             anti-tumor necrosis factor alpha agents) within 2 weeks prior to initiation of study
             treatment, or anticipation of need for systemic immunosuppressive medication during
             the course of the study, with the following exceptions:

               -  Patients who received acute, low-dose systemic immunosuppressant medication or a
                  one-time pulse dose of systemic immunosuppressant medication (e.g., 48 hours of
                  corticosteroids for a contrast allergy) are eligible. o Patients who received
                  mineralocorticoids (e.g., fludrocortisone), corticosteroids for chronic
                  obstructive pulmonary disease or asthma, or low-dose corticosteroids for
                  orthostatic hypotension or adrenal insufficiency are eligible for the study.

          -  Pregnant women are excluded from this study because the effects of ipatasertib and
             atezolizumab on a developing fetus are unknown. Breastfeeding should be discontinued
             prior to entry onto the study.