Introduction Evaluation of cirrhosis appears to be easily overlooked in the clinic for the HBsAg-negative (hepatitis B surface antigen-negative) and HBcAb-positive (hepatitis B core antibody-positive) population. Herein, we determine the prevalence of cirrhosis/advanced fibrosis among HBsAg-negative/HBcAb-positive US adults. Methods Data came from the National Health and Nutrition Examination Survey (NHANES) 2001-2018. A total of 3115 HBsAg-negative/HBcAb-positive US adults were enrolled in this study. We assessed cirrhosis by using the Fibrosis-4 (FIB-4) and aspartate aminotransferase to platelet ratio index (APRI) score. Results Out of 50,201 NHANES adults, 45,087 were tested for HBcAb/HBsAg, of whom 3115 met the inclusion criteria (HBsAg-negative/HBcAb-positive with available data for FIB-4/APRI). The weighted proportion of HBsAg-negative/HBcAb-positive among US adults was 4.46% (95% CI 4.17-4.75%), affecting 9.87 million US adults. According to the results of the FIB-4, the weighted prevalence of cirrhosis/advanced fibrosis among HBsAg-negative/HBcAb-positive US adults was 3.76% (95% CI 2.80-4.72%), which corresponds to 371,112 (95% CI 276,360-465,864) HBsAg-negative/HBcAb-positive American adults who had already developed cirrhosis. Among those, cirrhosis/advanced fibrosis in the HBsAb-negative (hepatitis B surface antibody) group (6.28%, 95% CI 4.10-8.45%) was significantly higher than in the HBsAb-positive group (3.08%, 95% CI 2.07-4.08%). Results were similar when APRI was used. Conclusion According to the FIB-4, 3.76% of HBsAg-negative and HBcAb-positive US adults had cirrhosis/advanced fibrosis, much higher than in the general population of the USA. Our data highlight the importance of cirrhosis screening in the HBsAg-negative/HBcAb-positive population to prevent advanced liver disease, especially in those who are HBsAb-negative.