The post-analytical phase of laboratory testing is increasingly recognized as a critical step in ensuring the quality and effectiveness of laboratory information. This phase involves the communication of laboratory results to users, including physicians, patients, and other stakeholders, and is essential for making informed clinical decisions. The harmonization of this phase is complex due to the involvement of multiple parties with different languages and perspectives. The laboratory report is a key component of this process, and its design and content must be standardized to ensure clarity, accuracy, and usability. The laboratory report should include essential information such as patient identity, sample receipt time, measurement units, reference intervals, and interpretative comments. Standardization of terminology, units, and reporting formats is crucial to ensure consistency and interoperability across different healthcare systems. The use of standardized systems like LOINC and SNOMED CT can enhance the clarity and utility of laboratory reports. Measurement uncertainty (MU) is an important aspect of laboratory reporting, as it provides information on the reliability of results. While MU is not always included in reports, its inclusion can improve the interpretation of results. Reference intervals (RI) and decision limits (DL) are also important tools for interpreting laboratory results, but there is ongoing debate about their use and the appropriate context for their application. Critical results reporting is another important aspect of the post-analytical phase, as it involves the timely notification of results that could have serious clinical implications. The notification of critical results must be reliable and efficient to ensure timely action. Interpretative comments are essential for providing context and guidance on laboratory results, helping clinicians make informed decisions. The harmonization of these comments is important to ensure consistency and quality. The intended recipients of laboratory reports, including both physicians and patients, influence the design and presentation of reports. Patients may benefit from reports that are easy to understand and use, and graphical representations can enhance the interpretation of results. Integrated diagnostics, which combine imaging, pathology, and laboratory tests with advanced information technology, are becoming increasingly important in healthcare. These approaches can improve the accuracy and efficiency of diagnostic processes. Artificial intelligence and machine learning are also playing a growing role in the post-analytical phase, helping to improve the interpretation and use of laboratory data. However, the standardization and harmonization of laboratory data are essential to ensure the reliability and effectiveness of these technologies. In conclusion, the post-analytical phase of laboratory testing is a critical component of laboratory medicine, and its harmonization is essential for improving the quality and effectiveness of laboratory information. Standardization, communication, and the use of advanced technologies are key to achieving this goal.The post-analytical phase of laboratory testing is increasingly recognized as a critical step in ensuring the quality and effectiveness of laboratory information. This phase involves the communication of laboratory results to users, including physicians, patients, and other stakeholders, and is essential for making informed clinical decisions. The harmonization of this phase is complex due to the involvement of multiple parties with different languages and perspectives. The laboratory report is a key component of this process, and its design and content must be standardized to ensure clarity, accuracy, and usability. The laboratory report should include essential information such as patient identity, sample receipt time, measurement units, reference intervals, and interpretative comments. Standardization of terminology, units, and reporting formats is crucial to ensure consistency and interoperability across different healthcare systems. The use of standardized systems like LOINC and SNOMED CT can enhance the clarity and utility of laboratory reports. Measurement uncertainty (MU) is an important aspect of laboratory reporting, as it provides information on the reliability of results. While MU is not always included in reports, its inclusion can improve the interpretation of results. Reference intervals (RI) and decision limits (DL) are also important tools for interpreting laboratory results, but there is ongoing debate about their use and the appropriate context for their application. Critical results reporting is another important aspect of the post-analytical phase, as it involves the timely notification of results that could have serious clinical implications. The notification of critical results must be reliable and efficient to ensure timely action. Interpretative comments are essential for providing context and guidance on laboratory results, helping clinicians make informed decisions. The harmonization of these comments is important to ensure consistency and quality. The intended recipients of laboratory reports, including both physicians and patients, influence the design and presentation of reports. Patients may benefit from reports that are easy to understand and use, and graphical representations can enhance the interpretation of results. Integrated diagnostics, which combine imaging, pathology, and laboratory tests with advanced information technology, are becoming increasingly important in healthcare. These approaches can improve the accuracy and efficiency of diagnostic processes. Artificial intelligence and machine learning are also playing a growing role in the post-analytical phase, helping to improve the interpretation and use of laboratory data. However, the standardization and harmonization of laboratory data are essential to ensure the reliability and effectiveness of these technologies. In conclusion, the post-analytical phase of laboratory testing is a critical component of laboratory medicine, and its harmonization is essential for improving the quality and effectiveness of laboratory information. Standardization, communication, and the use of advanced technologies are key to achieving this goal.