🔒 18 PHI Identifiers You Must Protect
HIPAA defines exactly 18 types of information that, when associated with health data, make it 'individually identifiable' and therefore Protected Health Information. To de-identify data using the Safe Harbor method, ALL 18 of these identifiers must be removed. As a database professional, you need to know every single one of these so you can find them in your client's systems, classify them, and ensure they are properly protected.
Names
Full name, last name, first name, maiden name, or any other name by which a person is known. This includes legal names, nicknames, and aliases used in healthcare records.
Found in: EHR systems (patient demographics), Billing records, Insurance claims, Appointment schedules, Lab orders and results, Prescription databases
Geographic Data Smaller Than a State
Any geographic subdivision smaller than a state, including street address, city, county, precinct, and ZIP code. ZIP codes CAN be included if only the first 3 digits are used AND the geographic area covered by those 3 digits has a population of more than 20,000. If the population is 20,000 or fewer, the 3-digit ZIP must be changed to 000.
Found in: Patient registration systems, Billing addresses, Provider directories, Referral records, Home health visit logs
Dates Related to an Individual
All dates (except year) directly related to an individual, including birth date, admission date, discharge date, date of death, and all ages over 89 (which must be aggregated into a single '90 or over' category). Years alone are generally permitted.
Found in: EHR demographic fields, Admission/discharge records, Lab specimen collection dates, Prescription fill dates, Appointment systems
Telephone Numbers
All telephone numbers associated with a patient, including home, work, mobile, and emergency contact numbers.
Found in: Patient registration forms, Contact databases, Appointment reminder systems, Emergency contact fields in EHR, Telehealth platforms
Fax Numbers
All fax numbers associated with a patient. Despite being considered outdated in many industries, fax remains widely used in healthcare for transmitting records between providers.
Found in: Provider communication logs, Referral records, Prescription records, Insurance correspondence, Legacy contact databases
Email Addresses
All email addresses associated with a patient, including personal and work email addresses used for patient portal access, appointment reminders, or any other healthcare communication.
Found in: Patient portal systems, Appointment reminder platforms, Secure messaging systems, Registration databases, Patient communication logs
Social Security Numbers
Social Security Numbers (SSNs) of patients. Many legacy healthcare systems collected SSNs as a primary identifier. Modern best practice is to avoid collecting SSNs unless absolutely necessary for billing or insurance purposes.
Found in: Legacy patient registration systems, Insurance enrollment databases, Medicaid/Medicare records, Billing systems, Financial assistance applications
Medical Record Numbers
Any number assigned by a healthcare provider to identify a patient's medical record within their system. These are unique identifiers created by the organization specifically for tracking patient records.
Found in: EHR systems (primary key), Lab information systems, Radiology systems, Pathology databases, Paper chart filing systems
Health Plan Beneficiary Numbers
Numbers assigned by health insurance plans to identify their members. This includes insurance ID numbers, member IDs, subscriber IDs, and policy numbers.
Found in: Insurance eligibility systems, Claims databases, Billing records, Referral authorization systems, Patient registration insurance fields
Account Numbers
Financial account numbers associated with a patient, including hospital account numbers, billing account numbers, and any other account identifiers used in the financial management of a patient's healthcare.
Found in: Hospital billing systems, Patient financial services databases, Collection agency records, Payment processing systems, Financial assistance records
Certificate/License Numbers
Any certificate or license numbers associated with a patient. This can include professional licenses, driver's licenses, or other identifying certificates that appear in healthcare records.
Found in: Patient identification records, Workers' compensation files, Motor vehicle accident records, Insurance application databases, Identity verification logs
Vehicle Identifiers and Serial Numbers
Vehicle identifiers and serial numbers, including license plate numbers and vehicle identification numbers (VINs), when they appear in healthcare records (typically in accident or injury records).
Found in: Emergency department trauma records, Motor vehicle accident reports, Workers' compensation files, Insurance claim narratives, Police report references in medical records
Device Identifiers and Serial Numbers
Identifiers and serial numbers for medical devices implanted in or associated with a patient. This includes pacemakers, insulin pumps, prosthetics, and any other device with a unique serial number.
Found in: Surgical records, Medical device registries, Implant tracking databases, EHR device sections, Recall notification systems
Web URLs (Universal Resource Locators)
Web addresses associated with a patient, such as personal websites, social media profiles, or any URLs that appear in healthcare records and can be linked to an individual patient.
Found in: Patient portal systems, Social worker referral notes, Mental health intake forms, Patient-provided information fields, Telehealth session logs
IP (Internet Protocol) Addresses
IP addresses associated with a patient's access to healthcare systems. In the age of telehealth and patient portals, IP addresses are increasingly common in healthcare system logs and can be used to identify or locate individuals.
Found in: Patient portal access logs, Telehealth platform logs, EHR audit trails, Secure messaging system logs, Online appointment scheduling systems
Biometric Identifiers
Biometric identifiers including finger and voice prints, retinal scans, facial recognition data, and any other unique biological measurement used to identify a patient. These are increasingly used for patient identification at check-in kiosks and for secure access to records.
Found in: Patient identity verification systems, Biometric check-in kiosks, Security access systems in healthcare facilities, Behavioral health monitoring systems, Research databases with biological samples
Full-Face Photographs and Comparable Images
Full-face photographic images and any comparable images that could identify a patient. This includes photos taken for identification, clinical photos (wound photos, dermatology images), and any images where the patient's face or identifying features are visible.
Found in: Patient registration photo systems, Clinical photography databases, Dermatology image libraries, Plastic surgery before/after records, Security camera footage linked to patient visits
Any Other Unique Identifying Number, Characteristic, or Code
Any other unique identifying number, characteristic, or code that could be used to identify an individual. This is a catch-all category that covers any identifier not listed above. It does NOT include codes assigned by the researcher for re-identification purposes in a de-identified dataset, as long as the code is not derived from the patient's actual identifiers.
Found in: Research databases, Clinical trial management systems, Genetic/genomic databases, Custom patient tracking systems, Cross-institutional patient matching systems