A spouse (or even the parent of a child over 18 years old) does not have an automatic right to see the medical records. That's why it's so important to fill out an Advance Health Care Directive (sometimes called a "Medical Power of Attorney") and a "HIPPA" waiver ("HIPPA" is an acronym for "Health Insurance Privacy Protection Act").
Without these documents, you may need to be appointed as your husband's conservator by the Probate Court - which takes time when time is at a premium and which costs 30 to 80 times more than the cost of getting the proper documents in place ahead of time.
If your husband is competent, he can sign these documents now.
If he is not competent, you will need a court order appointing you as conservator.
If he is deceased, you will need a court order appointing you as the executor or administrator of his probate estate.
The information you obtain at this site is not, nor is it intended to be, legal advice. You should consult an attorney for individual advice regarding your own situation.