There is no age limit for men when undergoing fertility treatment. Men, unlike women, do not have an age where fertility is drastically terminated.
Semen parameters such as concentration, motility, morphology or volume gradually decrease over time. Other semen parameters such as DNA fragmentation tend to increase as the years go by.
In general, all these semen changes and age-related diseases affect fertility and the results of reproductive treatments. However, in principle, there is no age limit where fertility treatments are inadvisable for males.