| Code | System | Display (en-US) |
| HP:0011460 | http://purl.obolibrary.org/obo/hp.owl | Embryonal onset |
| HP:0011461 | http://purl.obolibrary.org/obo/hp.owl | Fetal onset |
| HP:0003577 | http://purl.obolibrary.org/obo/hp.owl | Congenital onset |
| HP:0003623 | http://purl.obolibrary.org/obo/hp.owl | Neonatal onset |
| HP:0003593 | http://purl.obolibrary.org/obo/hp.owl | Infantile onset |
| HP:0011463 | http://purl.obolibrary.org/obo/hp.owl | Childhood onset |
| HP:0003621 | http://purl.obolibrary.org/obo/hp.owl | Juvenile onset |
| HP:0011462 | http://purl.obolibrary.org/obo/hp.owl | Young adult onset |
| HP:0003596 | http://purl.obolibrary.org/obo/hp.owl | Middle age onset |
| HP:0003584 | http://purl.obolibrary.org/obo/hp.owl | Late onset |