The Supreme court in Clark v. Rameker, 134 S. Ct. 2242, U.S. S.Ct, 6/12/2014, held that inherited IRAs are NOT EXEMPT, at least under federal law. The court did not address state law exemptions.
Before the Supremes weighed in on the issue, this topic was litigated heavily.
While IRAs are clearly exempt, there was a split in caselaw on the issue of whether inherited IRAs are also exempt. Cases seem to be trending to say that inherited IRAs they ARE exempt. One case saying otherwise was reversed by the Fifth Circuit in March 2012. (In re Chilton) Meanwhile, a recent 2013 decision from the 7th Circuit (In re Clark) has held that they are not exempt.
"Most of the courts that have analyzed this issue have concluded that inherited IRAs are "retirement funds" as that phrase is used in section 522(d)(12). Nessa, 426 B.R. at 314; In re Kuchta, 434 B.R. 837, 843-44 (Bankr. N.D. Ohio 2010); In re Tabor, 433 B.R. 469, 476 (Bankr. M.D. Pa. 2010); In re Thiem, 443 B.R. 832, 843-44 (Bankr. D. Ariz. 2011); In re Weilhammer, No. 09-15148-LT7, 2010 WL 3431465, at *4-*6 (Bankr. S.D. Cal. Aug. 30, 2010); In re Stephenson, U.S. Dist. LEXIS 142360, at *7-*8. These courts have noted that the statute does not explicitly limit "retirement funds" to retirement funds that belong to the debtor. See, e.g., Nessa, 426 B.R. at 314. Accordingly, they have reasoned that "retirement funds" can include the funds that others had originally set aside for their retirement, as with inherited IRAs. Id." In re Chilton
See also: http://www.ncbrc.org/tag/inherited-iras/
"The line of cases that deny exemptions in inherited IRAs commonly conclude that inherited IRAs are (1) fundamentally different from a traditional IRA under the IRC and (2) lack a retirement purpose. These courts determined that an inherited IRA is (1) subject to an entirely different set of rules upon the use, distribution and taxation of the funds, and (2) no longer for used for retirement purposes but is "a liquid asset which may be accessed by [the debtor] at his discretion withhout penalty, and which he must take as income within a relatively short period of time without regard for his retirement needs." In re Sims, 241 B.R. 467, 470 (Bankr.N.D.Okla. 1999) (Oklahoma law); see also In re Chilton, 426 B.R. 612 (Bankr.E.D.Tex.2010) (§ 522(d)(12)); In re Ard, 435 B.R. 719 (Bankr.M.D.Fla.2010) (Florida law and citing case law for § 522(d)(12), and citing Robertson v. Deeb, 16 So.3d 936 (Ct.App.2 Dist.2009)) (non-spousal inherited IRA not exempt from garnishment); In re Klipsch, 435 B.R. 586 (Bankr.S.D.Ind.2010) (Indiana law); In re Jarboe, 365 B.R. 717 (Bankr.S.D.Tex.2007) (Texas law); In re Taylor, 2006 WL 1275400, at *2 (Bankr. C.D.Ill.2006) (Illinois law); In re Navarre, 332 B.R. 24 (Bankr.M.D.Ala.2004) (Alabama law).
" In re Thiem 433 BR 823 (disagreeing with cited cases).