Inclusion Criteria:  All Participants:  Must have a clinically stable hepatic function as confirmed by the serum bilirubin and transaminase levels measured during screening and those measured on Day -1 Willing and able to adhere to the prohibitions and restrictions specified in this protocol If a woman, must not be of childbearing potential: postmenopausal (amenorrhea for at least 12 months and a serum follicle stimulating hormone within postmenopausal range); or surgically sterile (hysterectomy, bilateral salpingectomy, bilateral oophorectomy, bilateral tubal occlusion/ligation procedure)  Healthy Participants with normal hepatic function:  Blood pressure (after the participant is supine for 5 minutes) between 90 and 140 millimeter of mercury (mmHg) systolic for participants less than or equal to (<=) 60 years old and between 90 and 150 mmHg for participants greater than (>) 60 years old, inclusive, and no higher than 90 mmHg diastolic. If blood pressure is out of range, up to 2 repeated assessments are permitted per visit Pharmacogenomics: Healthy participants must have matching glutathione S-transferase Mu 1 (GSTM1) genotype (null or non-null GSTM1 genotype) to individual hepatic impairment group participants  Participants with hepatic impairment:  A 12-lead electrocardiogram (ECG) consistent with adequate cardiac conduction and function as per judgement by the investigator, including: a) Sinus rhythm; b) Heart rate between 50 and 100 beats per minute (extremes included); c) QTc interval <= 480 milliseconds (ms) (corrected cf. Fridericia; QTcF) Concomitant medications to treat underlying disease states or medical conditions related to hepatic impairment are allowed. Participants must be on a stable dose of medication and/or treatment regimen for at least 2 weeks before dosing as well as during the study  Exclusion Criteria:  All Participants:  Participant has known allergies, hypersensitivity, or intolerance to Lazertinib or its excipients Any surgical or medical condition that may alter the absorption, metabolism, or excretion of the study drug (example, gastrectomy, Crohn's disease etc.), with the exception of hepatic impairment Active gall bladder or biliary tract disease (example, acute cholecystitis, symptomatic cholelithiasis) Participant tests positive for human immunodeficiency virus (HIV)-1 or HIV-2 at screening Participant has a lack of adequate venous access