Can my child's father block my access to my child's medical records

You have exactly the same rights to the child's medical records as the custodial parent in New Jersey unless a court has placed some restriction on the non-custodial parent's rights to access such records. I would suggest contacting the pediatrician and remind them that under NJSA 9:2-4.2 the state grants both parents equal access to medical records. I am providing you with the citation. It may require a motion in court to force the doctor's office to release the records if they still refuse.  9:2-4.2 Parental access to children's records. 1. a. Every parent, except as prohibited by federal and State law, shall have access to records and information pertaining to his or her unemancipated child, including, but not limited to, medical, dental, insurance, child care and educational records, whether or not the child resides with the parent, unless that access is found by the court to be not in the best interest of the child or the access is found by the court to be sought for the purpose of causing detriment to the other parent.b.The place of residence of either parent shall not appear on any records or information released pursuant to the provisions of this section.c.A child's parent, guardian or legal custodian may petition the court to have a parent's access to the records limited. If the court, after a hearing, finds that the parent's access to the record is not in the best interest of the child or that the access sought is for the purpose of causing detriment to the other parent, the court may order that access to the records be limited.L.1997,c.406,s.1.