UNITED STATES COURT OF APPEALS

FOR THE TENTH CIRCUIT

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BRENT MIKELSON, 

 Plaintiff - Appellant,

v.

EMERSON CONRAD, III, M.D.; VAIL 

HEALTH, d/b/a Vail Health Hospital, 

 Defendants - Appellees.

No. 20-1271

(D.C. No. 1:20-CV-01545-PAB)

(D. Colo.)

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ORDER AND JUDGMENT*

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Before HARTZ, BALDOCK, and CARSON, Circuit Judges.

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The district court sua sponte dismissed Brent Mikelson’s complaint because he

failed to provide an evidentiary basis for the allegations in the complaint establishing 

diversity jurisdiction. Mr. Mickelson appeals. We exercise jurisdiction under 28 

U.S.C. § 1291 and reverse because the district court erroneously required additional 

evidence to support Mr. Mikelson’s well-pleaded allegations. 

*

 After examining the briefs and appellate record, this panel has determined 

unanimously that oral argument would not materially assist in the determination of 

this appeal. See Fed. R. App. P. 34(a)(2); 10th Cir. R. 34.1(G). The case is therefore 

ordered submitted without oral argument. This order and judgment is not binding 

precedent, except under the doctrines of law of the case, res judicata, and collateral 

estoppel. It may be cited, however, for its persuasive value consistent with 

Fed. R. App. P. 32.1 and 10th Cir. R. 32.1.

FILED

United States Court of Appeals

Tenth Circuit

January 5, 2021

Christopher M. Wolpert

Clerk of Court
2

Mr. Mikelson filed suit in the United States District Court for the District of 

Colorado alleging that while under anesthesia during surgery at Vail Health hospital 

he “suffered a severe hypoxic event that resulted in hypoxic/anoxic brain damage.” 

Aplt. App. at 6. His claims are for medical malpractice by the attending 

anesthesiologist, Dr. Emerson Conrad, and for vicarious liability against Vail Health

because of negligence by its employees. 

Mr. Mikelson asserted that the federal district court had jurisdiction under its 

diversity jurisdiction. See 28 U.S.C. § 1332(a) (“[D]istrict courts shall have original 

jurisdiction of all civil actions where the matter in controversy exceeds the sum or 

value of $75,000, exclusive of interest and costs, and is between . . . citizens of 

different States.”). The original complaint alleged that he was a resident of Alabama, 

that Dr. Conrad was a resident of Colorado, and that Vail Health was “a person” with 

a principal place of business in Colorado. Aplt. App. at 5. His complaint also 

alleged damages in excess of $75,000.

Before the defendants answered, the district court issued an order to show 

cause. The order stated that the allegations of the complaint were “insufficient to 

demonstrate the citizenship of the parties.” Id. at 10. It explained (1) that the 

complaint erroneously alleged Mr. Mikelson’s and Dr. Conrad’s residences rather 

than their domiciles, and (2) that the court was “unable to determine Vail Health’s 

citizenship” because the complaint failed to “allege what type of business entity Vail 

Health is.” Id. at 11. Because of the insufficient allegations it required Mr. Mikelson 
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to “show cause why th[e] case should not be dismissed . . . [for] lack of subject

matter jurisdiction.” Id. at 12.

Mr. Mikelson responded by filing an amended complaint. It alleged that he 

was domiciled in and a citizen of Alabama, that Dr. Conrad was domiciled in and a 

citizen of Colorado, and that Vail Health was a “Colorado corporation” with its 

principal place of business in Colorado. Id. at 16. The amended complaint was 

otherwise identical to the initial complaint. 

The district court then issued a second order to show cause. It said that the 

court was “still unable to determine the citizenship of any of the parties” because Mr. 

Mikelson failed to provide an “evidentiary basis” for his allegations. Id. at 21. The 

order also noted that Mr. Mikelson’s amended complaint failed to comply with the 

court’s local rules. Accordingly, the court provided Mr. Mikelson “one more 

opportunity” to show jurisdiction. Id. at 22. In response to the second show-cause 

order Mr. Mikelson refiled the same amended complaint, modified only to comply 

with the local rules. The court reviewed the refiled amended complaint and 

acknowledged that it complied with the local rules, but it concluded that it still failed 

to “address[] any of the jurisdictional deficiencies previously noted.” Id. at 25. The 

court dismissed the case before either defendant filed an answer. 

We review de novo the district court’s dismissal for lack of subject-matter 

jurisdiction. See Grynberg v. Kinder Morgan Energy Ptrs., 805 F.3d 901, 905 (10th 

Cir. 2015). A plaintiff bears the burden of establishing jurisdiction. See Dudnikov v. 

Chalk & Vermilion Fine Arts, 514 F.3d 1063, 1070 (10th Cir. 2008). But at the 
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pleading stage we “tak[e] as true all well-pled (that is, plausible, non-conclusory, and 

non-speculative) facts.” Id. (citation omitted).

To establish diversity among the parties the plaintiff must allege that all 

defendants are citizens of a different state than the plaintiff. See Grynberg, 805 F.3d 

at 905. Typically, a plaintiff satisfies this requirement by providing “a short and 

plain statement of the grounds for the court’s jurisdiction” in the complaint. Fed. R. 

Civ. P. 8(a)(1). For individuals, this jurisdictional statement must identify the 

person’s domicile. See Siloam Springs Hotel, L.L.C. v. Century Sur. Co., 781 F.3d 

1233, 1238 (10th Cir. 2015). For corporations, this statement must identify the state 

of incorporation and the state where the corporation maintains its principal place of 

business. See 28 U.S.C. § 1332(c)(1). 

Plaintiff’s amended complaint alleges that Mr. Mikelson is domiciled in and a 

citizen of Alabama, that Dr. Conrad is domiciled in and a citizen of Colorado, and 

that Vail Health is a Colorado corporation with its principal place of business in 

Colorado. These are well-pleaded allegations. As Mr. Mikelson explains, he did not 

merely allege that diversity exists; rather, he alleged the specific facts supporting 

diversity. This sufficed to establish complete diversity among the parties. See 

Grynberg, 805 F.3d at 905.

Despite these well-pleaded allegations the district court dismissed Mr. 

Mikelson’s complaint because he did not provide supporting evidence. True, a court 

can require an evidentiary showing of jurisdiction to resolve disputed facts or 

inadequate allegations. Cf. Dart Cherokee Basin Operating Co., LLC v. Owens, 574 
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U.S. 81, 87–89 (2014) (reversing district court for requiring evidentiary showing to 

support removal under Class Action Fairness Act; “‘a short and plain statement’” 

typically suffices for removal based on diversity jurisdiction, although additional 

evidence may be required where diversity allegations are contested (quoting 28 

U.S.C. § 1446(a))). And the district court correctly questioned Mr. Mikelson’s initial 

complaint because that complaint alleged Mr. Mikelson’s and Dr. Conrad’s 

residences rather than their domiciles, and it failed to identify whether Vail Health 

was a corporation or some other business entity. See Siloam Springs Hotel, L.L.C., 

781 F.3d at 1236–38. 

But critically, when the district court issued its first show-cause order, it 

repeatedly stated that the complaint’s “allegations [were] insufficient.” Aplt. App. at

10 (emphasis added). The show-cause order did not challenge the factual basis for 

the allegations or otherwise suggest that the complaint required evidentiary support. 

Thus, Mr. Mikelson’s revised allegations should have resolved this matter. No 

opposing party challenged the allegations. See Radil v. Sanborn W. Camps, Inc., 384 

F.3d 1220, 1224 (10th Cir. 2004) (court may consider evidence “[w]here a party 

attacks the factual basis for subject matter jurisdiction” (emphasis added)). And, as 

Mr. Mikelson notes, the court never explained why it doubted the revised 

allegations—either in its second show-cause order or in its order dismissing the 

complaint. Because Mr. Mikelson’s amended complaint sufficiently alleged the basis 

for diversity jurisdiction, the district court erred in dismissing the complaint. 
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We REVERSE the district court’s order dismissing the complaint and 

REMAND for further proceedings consistent with this Order.

Entered for the Court

Harris L Hartz

Circuit Judge