⁃ Subject must meet all of the following applicable inclusion criteria to participate in this study:

• Written informed consent and HIPAA authorization for release of personal health information must be obtained either from the subject or their representative. See protocol. NOTE: HIPAA authorization may be included in the informed consent or obtained separately.

• Age ≥ 18 years at the time of consent.

• ECOG Performance Status of 0-1.

• Locally advanced, metastatic, or unresectable hepatocellular carcinoma that has not received prior systemic therapy. Note: if no prior histologic diagnosis exists, prefer fresh biopsy if it is both safe and feasible. If fresh biopsy is not safe and feasible, imaging criteria may be used for diagnosis as per AASLD criteria in cirrhotic patients (please see www.aasld.org for up to date guidelines).

• Child Pugh Class B7 or B8 liver dysfunction or cirrhosis with the following limitations:

‣ Bilirubin ≤ 3 mg/dL

⁃ Albumin ≥ 2.8 g/dL

⁃ INR ≤ 1.7

⁃ Absent to slight \[CP=1 to 2\] (no moderate \[CP=3\]) ascites (Also see exclusion criteria).

⁃ No clinically significant encephalopathy (Also see exclusion criteria).

• At least 1 untreated measurable lesion according to RECIST 1.1.

• Willingness to undergo fresh tumor biopsy at baseline if safe and feasible. Note: archival tissue may be used at baseline provided histologic diagnosis was made and sufficient tissue is available for NGS analysis.

• NGS analysis must be requested from archival tissue or fresh biopsy (if applicable) as per standard of care. Foundation One CDX is the preferred platform. Prior NGS sequencing results (including from another platform) will be accepted if NGS sequencing was previously obtained (please see protocol).

• Demonstrate adequate bone marrow and organ function as defined below:

‣ Hematologic

• Absolute neutrophil count (ANC) ≥ 1,000/mcL

∙ Lymphocyte count ≥ 0.5 x 10\^9/L (500uL)

∙ Hemoglobin ≥ 90 g/L (9 g/dL)

∙ Platelet count ≥ 70,000/mcL

⁃ Renal

• Serum creatinine OR calculated\* serum creatinine clearance (GFR can be used in place of creatinine or creatinine clearance) ≤ 1.5 x ULN OR ≥ 30 mL/min for participants with creatinine levels \> 1.5 x institutional ULN \*calculate serum creatinine clearance using the standard Coccroft-Gault formula

∙ Urine protein: Urine dipstick for proteinuria \< 2+ within 7 days prior to start of study treatment \*Patients with with ≥ 2+ proteinuria on dipstick analysis at baseline should undergo a 24-hour urine collection which must demonstrate \< 1g of protein in 24 hours.

⁃ Hepatic

• AST (SGOT) and ALT (SGPT) ≤ 8 x ULN

∙ Alkaline phosphastase (ALP) ≤ 8 x ULN

• For women of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive methods with a failure rate of \< 1% per year during the treatment period and for at least 5 months after the last dose of atezolizumab, or 6 months after the last dose of bevacizumab. See also the protocol for definition of childbearing potential.

• For men: agreement to remain abstinent (refrain from heterosexual intercourse) or use effective contraceptive measures. Men with female partners of childbearing potential must remain abstinent or use a condom plus an additional contraceptive method that together result in a failure rate of \< 1% per year during the treatment period and for 6 months after the last dose of bevacizumab. With pregnant female partners, men must remain abstinent or use a condom during the treatment period and for 6 months after the last dose of bevacizumab to avoid exposing the embryo. See also the protocol for additional information.

• As determined by the enrolling physician or protocol designee, ability of the subject to understand a written informed consent document, and ability and willingness to comply with study procedures for the entire length of the study. Patients with impaired decision-making capacity (IDMC) who have a close caregiver or legally authorized representative (LAR) and/or family member available are also eligible.