States that assumed contractual obligations without establishing them as of 2000:
Colorado, see Even v. Longmont United Hosp. Ass'n, 629 P.2d 1100, 1103 (Colo. Ct. App. 1981)
Massachusetts, see Duby v. Jordan Hosp., 341 N.E.2d 876, 879 (Mass. 1976)
Mississippi, see Wong v. Stripling, 700 So. 2d 296, 300-02 (Miss. 1997)
Ohio, see Bouquett v. St. Elizabeth Corp., 538 N.E.2d 113, 115-16 (Ohio 1989)
Oklahoma, see Ponca City Hosp., Inc. v. Murphree, 545 P.2d 738, 742 (Okla. 1976)
Virginia, see Medical Ctr. Hosps. v. Terzis, 367 S.E.2d 728, 729 (Va. 1988)

States where "medical staff bylaws alone are not a contract, but, in the context of the entire relationship between the physicians and the hospital, they are enforceable as part of a larger contractual relationship":

Connecticut, see Gianetti v. Norwalk Hosp., 557 A.2d 1249, 1252-55 (Conn. 1989); Owens v. New Britain Gen. Hosp., 643 A.2d 233, 239 n.25 (Conn. 1994)

States where the medical staff bylaws are not a contract:

Georgia, see St. Mary's Hosp., Inc. v. Radiology Prof'l Corp., 421 S.E.2d 731, 736 (Ga. Ct. App. 1992)
Iowa, see Tredrea v. Anesthesia & Analgesia, P.C., 584 N.W.2d 276, 284-87 (Iowa 1998) (establishing requirements for bylaws to qualify as a contract)
Mississippi, see Sullivan v. Baptist Mem'l Hosp. - Golden Triangle, Inc., 722 So. 2d 675, 680-81 (Miss. 1998) (but see above)
Missouri, see Zipper v. Health Midwest, 978 S.W.2d 398, 415-17 (Mo. Ct. App. 1998) (but equitable relief is available under bylaws)
North Dakota, see Robles v. Humana Hosp. Cartersville, 785 F. Supp. 989, 1001 (N.D. Ga. 1992)
Ohio, see Munoz v. Flower Hosp., 507 N.E.2d 360, 365 (Ohio Ct. App. 1985) (lack of contract because lack of mutuality of obligation); Holt v. Good Samaritan Hosp. & Health Ctr., 590 N.E.2d 1318, 1322 (Ohio Ct. App. 1990)

States where hospital bylaws are contractually binding on a hospital, but not medical staff bylaws:

Iowa, see Tredrea v. Anesthesia & Analgesia, P.C., 584 N.W.2d 276, 284-87 (Iowa 1998)
Maryland, see Ishak v. Fallston Gen. Hosp. & Nursing Ctr., 438 A.2d 1369, 1372 (Md. Ct. Spec. App. 1982)
Texas, see Gonzalez v. San Jacinto Methodist Hosp., 880 S.W.2d 436, 438-39 (Tex. Ct. App. 1994) (but see above)
Tennessee rejects the distinction, see Lewisburg Cmty. Hosp., Inc. v. Alfredson, 805 S.W.2d 756, 759 (Tenn. 1991)