He did not fast Ramadan because of sickness 25 years ago and he has not made it up until now
Question

                My husband was bitten by a snake twenty-five years ago, one day before Ramadan, and he was in a critical state for two months. The following year he did not fast for ten days, until the doctor allowed him to fast. And my husband was not able to feed poor people because he was very poor. Does he have to make up the fast and feed poor people because now he is well off, praise be to Allah?.
Praise be to Allah.
    Firstly: 

    Putting off asking about the Islamic ruling on this matter 
    for such a long time is clear heedlessness. Your husband should have asked 
    about that immediately after he was bitten by that snake, especially since 
    it was only one day before Ramadan. 

    Your husband has to repent to Allah for this delay, and he 
    has to regret it and resolve not to do such a thing again. And we ask Allah 
    to accept his repentance. 

    Secondly: 

    Sickness is one of the excuses that make it permissible not 
    to fast during Ramadan, based on the text of the Holy Qur’aan and the 
    consensus of the scholars. 

    Ibn Qudaamah said in al-Mughni (1/42-43): 

    The scholars are unanimously agreed that it is permissible in 
    general for sick people not to fast. The basis for that is the verse in 
    which Allah says (interpretation of the meaning): 

    “But if any of you is ill or on 
    a journey, the same number (should be made up) from other days”

    [al-Baqarah 2:184]. 

    This sickness that makes it permissible not to fast is severe 
    sickness that will be made worse by fasting or there is the fear that 
    fasting will delay recovery. End quote. 

    If a person breaks the fast because of sickness, his case 
    should be examined further. 

    If it was a sickness for which there was no hope of healing 
    or recovery, then he has to pay the fidyah (ransom), which is to feed one 
    poor person for each day that he did not fast. Then the scholars differed if 
    the person is poor and not well off – does he have to pay the fidyah if he 
    becomes well off or is it waived in his case? 

    But if there was the hope of healing and recovery from his 
    sickness, then he should wait until he recovers and make up the days that he 
    missed, and he does not have to pay the fidyah. Also it is not permissible 
    for him to move from making up the fast to paying the fidyah instead. 

    Al-Nawawi said in al-Majmoo‘, 6/261-262: 

    If a person is sick and is unable to fast because of sickness 
    that he hopes to recover from, he does not have to fast at present, but he 
    has to make it up. This applies if he will face considerable difficulty in 
    fasting. End quote. 

    Ibn Qudaamah said in al-Mughni, 3/82: 

    The sick person who has no hope of recovery may not fast, and 
    he should feed one poor person for each day… this is understood to apply to 
    the one who has no hope of becoming able to make up the fasts. If he does 
    hope to become able to do so, then he does not have to offer the fidyah, and 
    he has to delay making up the fasts and do that when he becomes able to do 
    it, because Allah says (interpretation of the meaning):

    “But if any of you is ill or on 
    a journey, the same number (should be made up) from other days”

    [al-Baqarah 2:184].

    He only moves on to paying the fidyah instead if he loses 
    hope of becoming able to make up the fasts. End quote. 

    What seems to us to be the case -- and Allaah knows best -- 
    is that what befell your husband was a temporary sickness from which he 
    hoped to recover, and indeed Allah healed him. So he has to make up the days 
    that he did not fast because of that sickness; it is not sufficient for him 
    to feed the same number of poor people as the days he missed. 

    But, if he feeds poor people as well as making up those days, 
    this is on the safe side, especially since you say that he is now well off, 
    praise be to Allah. 

    See also the answer to question no.
    26865 

    And Allah knows best.