Probability of Paternity
Quick answer
The final percentage on a paternity report — usually 99.99%+ (inclusion) or 0% (exclusion).
Probability of Paternity is derived from the CPI and a Bayesian prior. In practice, results are either 99.99%+ (biological father) or 0% (excluded). Values between 90% and 99.99% are extraordinarily rare with a modern 34-marker test.
Browse the glossary
- AABB Accreditation
- STR Marker
- 34-Marker Paternity Test
- Combined Paternity Index (CPI)
- Probability of Paternity
- Chain of Custody
- Buccal Swab
- Cheek Swab
- Non-Invasive Prenatal Paternity (NIPP)
- Cell-Free Fetal DNA (cffDNA)
- Amniocentesis
- Chorionic Villus Sampling (CVS)
- USCIS Genetic Testing
- Form I-130
- Legal Paternity Test
- Home Paternity Test
- How It Works
- CLIA Certification
- ISO/IEC 17025
- College of American Pathologists (CAP)
Ready for a clear answer?
AABB-accredited lab. All fees included. Results in 1–2 business days.