My husband is incarcerated, has been since October 2012, the grand jury has met 3 times and has not indicted him, how long can this go on without him being indicted

Is it a federal offense he is being charged with?
From policyarchive.org: "There is no statute of limitations for federal crimes punishable by death, nor for certain federal crimes of terrorism, nor, since passage of the Adam Walsh Child Protection and Safety Act (P.L. 109-248, H.R. 4472, 2006), for certain federal sex offenses. Prosecution for most other federal crimes must begin within five years of the commitment of the offense. There are exceptions. Some types of crimes are subject to a longer period of limitation; some circumstances suspend or extend the otherwise applicable period of limitation.
Arson, art theft, certain crimes against financial institutions and various immigration offenses all carry statutes of limitation longer than the five year standard. Regardless of the applicable statute of limitations, the period may be extended or the running of the period suspended or tolled under a number of circumstances such as when the accused is a fugitive or when the case involves charges of child abuse, bankruptcy, wartime fraud against the government, or DNA evidence."

Then, depending on the classification of felony or misdemeanor, of which there can be different types, it goes by state law how long he can be held without indictment. Not all states have such a statute, and most people held as long as your husband are there because they couldn't make bail.

Do you wish to tell us about the charges, being given a bail amount, and what state?