When a guaranty is entered into at the same time with the original obligation or with the acceptance of the original obligation by the person making the guaranty and forms with that original obligation a part of the consideration to the person, no other consideration need exist. In all other cases, there must be a consideration distinct from that of the original obligation.
Mont. Code Ann. § 28-11-103
When separate consideration required
En
Official source: Montana Code Annotated (Montana Legislature). Reproduced from public-domain Montana statutes; confirm against the official source for the current text. Not legal advice.