What is Personally Identifiable Information (PII) & Personal Health Information (PHI)?

Protecting Personally Identifiable Information (PII) is essential. Understand the regulations and strategies for safeguarding sensitive data.
Author: SentinelOne Updated: July 21, 2025

Personally Identifiable Information (PII) and Personal Health Information (PHI) are critical data types that require stringent protection. This guide explores the definitions, examples, and legal implications of PII and PHI.

Learn about the risks associated with data breaches and the importance of implementing robust data protection measures. Understanding PII and PHI is essential for organizations to comply with regulations and protect sensitive information from unauthorized access.

A Brief Overview of Personally Identifiable Information (PII) & Personal Health Information (PHI)

PII refers to any information that can be used to identify an individual, including but not limited to names, addresses, social security numbers, phone numbers, email addresses, financial data, and more. The development of PII can be traced back to the increasing digitization of personal information, spurred by the rise of the internet, e-commerce, and online communication platforms. Today, PII is used in a multitude of applications, from online account creation to financial transactions and social media profiles. Its unauthorized access or exposure poses significant risks, including identity theft, fraud, and privacy invasion.

PHI, on the other hand, focuses exclusively on sensitive health-related data. It encompasses patient records, medical histories, treatment details, insurance information, and any data related to an individual’s health or healthcare. PHI’s development is closely tied to the advancement of electronic health records (EHR) and the digitization of the healthcare industry. In contemporary healthcare systems, PHI plays a central role, enabling healthcare providers to deliver efficient and patient-centric care. However, the protection of PHI is crucial for health providers given the potential consequences of breaches, such as medical identity theft, unauthorized disclosure, or misuse of health-related information.

Today, both PII and PHI are at the forefront of cybersecurity concerns. Laws and regulations, such as the Health Insurance Portability and Accountability Act (HIPAA) for PHI and various data protection acts for PII, have been enacted to enforce data security standards and hold organizations accountable for safeguarding these sensitive data categories.

How to Secure Personally Identifiable Information (PII) & Personal Health Information (PHI)

Regulatory frameworks for protecting Personally Identifiable Information (PII) and Personal Health Information (PHI) are vital in today’s digital landscape, as they set standards and requirements to safeguard sensitive data. These frameworks are designed to ensure the confidentiality, integrity, and availability of PII and PHI while providing individuals with greater control over their personal information. Businesses that handle these types of data are subject to these regulations and have implemented a range of measures to achieve compliance.

Regulatory Frameworks for PII include:

  • General Data Protection Regulation (GDPR) – The GDPR is a comprehensive European Union regulation that applies to organizations worldwide if they process the data of EU residents. It sets stringent requirements for data protection, consent, and individual rights. Businesses must obtain explicit consent to process PII, provide data subjects with access to their data, and implement robust security measures to protect this information.
  • California Consumer Privacy Act (CCPA) – The CCPA is a state-level regulation in the U.S., specifically applying to businesses that collect and sell personal information of California residents. It grants consumers the right to know what data is collected, request deletion of their data, and opt-out of data sales.

Regulatory Frameworks for PHI include:

  • Health Insurance Portability and Accountability Act (HIPAA) – HIPAA primarily addresses the confidentiality and security of PHI. It mandates strict controls on access to PHI, encryption of electronic PHI, and the implementation of safeguards to protect against unauthorized access or disclosure.
  • Health Information Technology for Economic and Clinical Health Act (HITECH Act) – HITECH Act expanded HIPAA’s reach by strengthening enforcement and increasing penalties for non-compliance. It also promotes the adoption of electronic health records (EHR) and provides incentives for their meaningful use.

These regulatory frameworks establish guidelines and requirements that organizations must follow to protect PII and PHI. They typically include the following key elements:

  • Data Protection Principles – Both GDPR and HIPAA define principles that require organizations to handle PII and PHI responsibly. This includes principles related to data minimization, purpose limitation, data accuracy, and storage limitation.
  • Consent – GDPR mandates obtaining clear and explicit consent from data subjects before processing their PII. This principle ensures individuals have control over how their information is used. HIPAA, on the other hand, doesn’t require consent but necessitates informing patients about their rights concerning their PHI.
  • Data Security – Data security is a fundamental aspect of these frameworks. They require organizations to implement technical and organizational measures to protect PII and PHI from unauthorized access, disclosure, alteration, or destruction. This includes encryption, access controls, and regular security assessments.
  • Data Breach Notification – Both GDPR and HIPAA have provisions for data breach notification. Organizations must report data breaches to relevant authorities and affected individuals within specific timeframes. This allows individuals to take necessary precautions in case of a breach.
  • Individual Rights – GDPR provides individuals with a range of rights over their PII, including the right to access, rectify, and erase their data. HIPAA grants patients rights to access their PHI and request corrections.

What Businesses Are Doing to Ensure Data Compliance

Businesses that handle PII and PHI have implemented various measures to achieve and maintain compliance with these regulatory frameworks:

  • Data Encryption – Businesses use encryption to protect PII and PHI during storage, transmission, and processing. This ensures that even if unauthorized access occurs, the data remains confidential and unreadable.
  • Access Controls – Robust access controls are crucial to limit who can access PII and PHI. This includes role-based access and user authentication mechanisms to ensure only authorized individuals can view or modify the data.
  • Regular Audits and Assessments – Organizations conduct routine audits and security assessments to identify vulnerabilities, weaknesses, or compliance gaps. These assessments help in proactively addressing issues before they become major problems.
  • Privacy Impact Assessments – GDPR mandates conducting Privacy Impact Assessments (PIAs) to evaluate the impact of data processing activities on data subjects’ privacy. Businesses use PIAs to identify and mitigate risks.
  • Data Retention Policies – Implementing data retention policies ensures that PII and PHI are not retained longer than necessary. This aligns with the principle of storage limitation in GDPR.
  • Data Breach Response Plans – Businesses have in place data breach response plans that outline steps to take in case of a security incident. Rapid response and notification are essential to meet compliance requirements.
  • Employee Training – Employee training and awareness programs are critical. Staff members handling PII and PHI should be knowledgeable about data protection regulations, best practices, and security protocols.
  • Audit Trails and Monitoring – Robust auditing and monitoring mechanisms track access and usage of PII and PHI. These audit trails help organizations identify unauthorized or suspicious activities and maintain compliance.
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Conclusion

In a world where cyber threats are continually evolving, the protection of PII and PHI is a keystone in identity security. Organizations and individuals must implement robust defense measures, including encryption, access controls, regular audits, and employee training to ensure that these data types remain confidential and secure.

FAQs

What is Personally Identifiable Information PII?

Personally identifiable information (PII) is any data that could identify a specific individual. This includes information that can distinguish one person from another and can be used alone or combined with other data to trace someone’s identity.

PII encompasses direct identifiers like Social Security numbers and names, as well as quasi-identifiers like date of birth and gender that become identifying when combined. Organizations must protect PII due to legal requirements and to prevent identity theft, financial fraud, and reputational damage from data breaches.

What is PHI Personal Health Information?

PHI (Protected Health Information) refers to individually-identifiable health information created, received, or maintained by healthcare providers. This includes demographic information, medical histories, test results, physical and mental health conditions, and payment information for healthcare services.

PHI is protected under HIPAA regulations and can be in oral, written, or electronic form. This also includes any health-related data that can be linked to a specific individual and is used in the course of providing healthcare services.

What is an Example of PII Personally Identifiable Information?

Examples of sensitive PII include Social Security numbers, passport numbers, driver’s license numbers, credit card information, financial account details, and biometric data like fingerprints. Non-sensitive PII examples include full names, email addresses, phone numbers, dates of birth, ZIP codes, and workplace information.

When combined, non-sensitive data can become identifying – for instance, a name with birthdate and ZIP code can uniquely identify someone. Medical records, login credentials, and home addresses are also common PII examples that require protection.

What is Considered Personally Identifiable Information PII?

PII includes any data that can identify a specific person either directly or when combined with other information. This encompasses direct identifiers that uniquely identify someone and quasi-identifiers that create unique identification when combined. The definition includes traditional elements like names and Social Security numbers, but has expanded to cover digital identities including IP addresses, social media posts, and online login information.

Even data that could be used in de-anonymization techniques is considered PII, and the sensitivity increases when combinations of elements enhance the ability to identify specific individuals.

What are the 4 Types of PHI?

The four main categories of PHI include demographic identifiers (names, addresses, dates), contact information (phone numbers, email addresses), unique identifiers (Social Security numbers, medical record numbers, account numbers), and technical identifiers (IP addresses, device identifiers, biometric data). These categories encompass all 18 HIPAA identifiers that make health information personally identifiable.

PHI can exist in oral, written, or electronic form and must be protected when used in healthcare contexts. Each category requires specific handling and protection measures under HIPAA regulations.

What are the 7 Identifiers of PHI?

Seven key PHI identifiers include names, addresses (geographic subdivisions smaller than state), dates related to individuals (birth, admission, discharge), telephone numbers, email addresses, Social Security numbers, and medical record numbers.

Additional identifiers encompass account numbers, certificate/license numbers, vehicle identifiers, device identifiers, biometric identifiers, photographic images, and any unique identifying characteristics. All 18 identifiers must be removed for data to be considered de-identified under HIPAA safe harbor rules. These identifiers become PHI when linked with health information and require protection under federal privacy laws.

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