This paper presents high-precision radiocarbon age calibration for terrestrial and marine samples, extending the calibration range back to 9668 cal BC. The authors tabulate and discuss single-year and decadal radiocarbon tree-ring ages, providing a detailed 14C age calibration curve for the period AD 1510–1954. The Seattle decadal data set, extending back to 11,617 cal BP, is a component of the INTCAL98 14C age curve. The paper also discusses the transformation of atmospheric 14C ages into global ocean 14C ages using a carbon reservoir model, yielding results slightly different from previously published values. The authors address offsets, error multipliers, regional 14C age differences, and the response of marine 14C ages to oceanic and atmospheric forcing. They provide corrections for radon contamination in 14C measurements and discuss regional offsets relative to Washington, including samples from Alaska, Russia, Tasmania, and South Chile. The paper includes comparisons of 14C dates from different laboratories and the impact of laboratory offsets in pine and bristlecone pine data. Single-year age calibration and marine 14C age calibration are also discussed, with a focus on the influence of oceanic circulation changes on 14C reservoir ages. The latest version of the CALIB program incorporates the single-year and decadal data sets for terrestrial and marine environments.This paper presents high-precision radiocarbon age calibration for terrestrial and marine samples, extending the calibration range back to 9668 cal BC. The authors tabulate and discuss single-year and decadal radiocarbon tree-ring ages, providing a detailed 14C age calibration curve for the period AD 1510–1954. The Seattle decadal data set, extending back to 11,617 cal BP, is a component of the INTCAL98 14C age curve. The paper also discusses the transformation of atmospheric 14C ages into global ocean 14C ages using a carbon reservoir model, yielding results slightly different from previously published values. The authors address offsets, error multipliers, regional 14C age differences, and the response of marine 14C ages to oceanic and atmospheric forcing. They provide corrections for radon contamination in 14C measurements and discuss regional offsets relative to Washington, including samples from Alaska, Russia, Tasmania, and South Chile. The paper includes comparisons of 14C dates from different laboratories and the impact of laboratory offsets in pine and bristlecone pine data. Single-year age calibration and marine 14C age calibration are also discussed, with a focus on the influence of oceanic circulation changes on 14C reservoir ages. The latest version of the CALIB program incorporates the single-year and decadal data sets for terrestrial and marine environments.