[DO NOT PUBLISH]

IN THE UNITED STATES COURT OF APPEALS

FOR THE ELEVENTH CIRCUIT

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No. 19-11909

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D.C. Docket No. 1:18-cr-20473-MGC-1

UNITED STATES OF AMERICA, 

 Plaintiff-Appellee,

 versus

YAMILET DIAZ, 

 Defendant-Appellant.

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Appeal from the United States District Court

for the Southern District of Florida

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(February 24, 2021)

Before JORDAN, JILL PRYOR, and BRANCH, Circuit Judges.

PER CURIAM: 

Yamilet Diaz appeals her convictions for one count of conspiring to defraud 

the United States and four counts of receiving illegal health care kickbacks for 

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referring individuals to Medicare in violation of 18 U.S.C. § 371 and 42 U.S.C. § 

1320a-7b(b)(1)(A). Following oral argument and a careful review of the parties’ 

briefs and the record, we affirm. 

I

The evidence at trial demonstrated that Ms. Diaz participated in an illicit 

business arrangement with Suley Cao. Pursuant to this arrangement, Ms. Diaz 

referred Medicare beneficiaries to Good Friends Services, Inc., a Medicare-approved 

home health care provider operated by Ms. Cao. 

A

Rogelio Rodriguez incorporated and owned a company called Caring Nurse 

and obtained approval to become a Medicare provider. Mr. Rodriguez paid Cristobal 

Gonzalez and others to act as patient providers for Caring Nurse, and Mr. Gonzalez 

steered patients to Caring Nurse in exchange for kickbacks. Mr. Gonzalez then 

submitted fake invoices to Caring Nurse for services rendered on behalf of his 

company, Florida Network Providers (FNP), to cover up the kickbacks.

Ms. Diaz worked with Mr. Gonzalez and was the registered agent, an officer,

and a director of FNP, as well as an authorized signer on FNP’s bank account. Mr. 

Gonzalez later introduced Ms. Diaz to Mr. Rodriguez, and the two worked together. 

Mr. Rodriguez was subsequently arrested, charged, and convicted of conspiracy to 

commit Medicare fraud. 

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After Mr. Rodriguez’s arrest, Ms. Diaz contacted Ms. Cao, the owner of a 

home health care agency called Good Friends, and arranged a meeting with her. At 

the meeting, Ms. Diaz proposed working with Ms. Cao and steering Medicare 

beneficiaries to Good Friends for $2,000 per patient. The two agreed to payment by 

check with an increased rate of $2,200 per patient to account for Ms. Cao not being 

able to pay with cash. The checks were made out to Consulting Billing Services, a 

company incorporated by Ms. Diaz. Ms. Diaz and Ms. Cao then implemented their 

plan. Ms. Cao documented their exchanges and details about the Medicare patients 

in a ledger. 

Ms. Diaz began dating Hector Hernandez in 2011. Through him, Ms. Diaz 

met Abigail Aguila. After finding out they both had the same type of job, Ms. Diaz 

eventually introduced Ms. Aguila to Ms. Cao. At the meeting, Ms. Aguila and Ms. 

Cao agreed to work together, and they discussed Ms. Cao paying Ms. Aguila 

kickbacks in Ms. Diaz’s presence. 

B

A grand jury returned an indictment against Ms. Diaz on June 5, 2018,

charging her with one count of conspiracy to defraud the United States by receiving 

illegal health care kickbacks in violation of 18 U.S.C. § 371 and four counts of 

receiving illegal health care kickbacks in violation of 42 U.S.C. § 1320a7b(b)(1)(A). Ms. Diaz pled not guilty and the case proceeded to trial.

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At trial, the jury heard testimony from Stephen Quindoza, an expert witness 

on Medicare processes; Mr. Rodriguez; Ms. Aguila; Ms. Cao; Mr. Hernandez; Jarett 

Iliff, an investigator for the Department of Health and Human Services; Precious 

Sanchez, a forensic accountant; and Ms. Diaz. The jury found Ms. Diaz guilty on 

all five counts. The district court later sentenced Ms. Diaz to 87 months of 

imprisonment followed by 36 months of supervised release. This appeal followed.

II

Ms. Diaz contends that the district court erred when it denied her motion to 

exclude Rule 404(b) and inextricably intertwined evidence. The district court ruled

that evidence of her prior involvement with other home health care agencies was 

admissible to prove her intent and that it was inextricably intertwined with the 

charged conduct. 

Ms. Diaz argues that the evidence of her prior involvement with other home 

health care agencies in patient-referral schemes should not have been admitted 

because it did not satisfy Rule 404(b) or the test for admission of prior acts to prove 

intent. She claims that the evidence was unfairly prejudicial; that it lacked the factual 

basis to prove intent; and that it was not inextricably intertwined with the charged 

conduct. The government responds that the district court did not err because the 

evidence was intrinsic to the charged conduct, as well as admissible to prove intent

under Rule 404(b). 

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We review rulings on admission of prior bad-act evidence for abuse of 

discretion. See United States v. Cooper, 926 F.3d 718, 733 (11th Cir. 2019). Rule 

404(b) generally precludes the admission of evidence “of a crime, wrong, or other 

act . . . to prove a person’s character” or to show that the person acted in conformity 

with his or her prior act. See Fed. R. Evid. 404(b)(1); United States v. Nerey, 877 

F.3d 956, 974 (11th Cir. 2017). But Rule 404(b) provides several exceptions to the 

exclusion of such evidence, including for the purpose of proving intent. See Fed. R. 

Evid. 404(b)(2). Additionally, Rule 404(b) does not apply, and the evidence need 

not meet one of the admissible categories in Rule 404(b)(2), if “it is (1) part of the 

same transaction or series of transactions as the charged offense, (2) necessary to 

complete the story of the crime, or (3) inextricably intertwined with the evidence 

regarding the charged offense.” Nerey, 877 F.3d at 974 (citing United States v. 

Baker, 432 F.3d 1189, 1205 n.9 (11th Cir. 2005)). Rule 403 gives a district court 

the discretion to exclude otherwise admissible evidence (including Rule 404 

evidence) if its probative value is substantially outweighed by the danger of unfair 

prejudice. See Fed. R. Evid. 403; United States v. Shabazz, 887 F.3d 1204, 1216 

(11th Cir. 2018).

In Nerey, 877 F.3d at 975, evidence of a defendant’s “involvement with other 

home health care agencies . . . was inextricably intertwined with, and probative of,

how [the defendant] became involved with the home health care agencies” at issue. 

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Here, the evidence is almost identical to that in Nerey: Ms. Cao testified that Ms. 

Diaz was referred to her as a result of Ms. Diaz’s work recruiting patients for other 

home health care agencies. The evidence of Ms. Diaz’s involvement with other 

home health care agencies explains how she came to know Ms. Cao and joined the 

conspiracy she was found guilty of. It was therefore inextricably intertwined and 

admissible on that basis alone. Ms. Diaz’s prior involvement was also highly

probative of her intent under Rule 404(b)(2) and was not substantially outweighed 

by the risk of unfair prejudice. Thus, the district court did not abuse its discretion 

when it denied her motion to exclude.

III

Ms. Diaz argues that the district court erred when it denied her motion to 

dismiss the indictment against her for prejudicial pre-indictment delay. We have 

previously reviewed the denial such of a motion for abuse of discretion and the 

underlying factual findings for clear error. See United States v. Foxman, 87 F.3d 

1220, 1222–23 (11th Cir. 1996). We apply that standard here. 

For Ms. Diaz to prove a due process violation from pre-indictment delay, she 

must show (1) that there was actual prejudice to her defense and (2) that the 

government’s delay was deliberate to gain a tactical advantage. See United States v. 

Gouveia, 467 U.S. 180, 192 (1984). See also United States v. Thomas, 62 F.3d 1332, 

1339 (11th Cir. 1995). This standard applies even when the government brings

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charges within the statute of limitations, as is the case here. See Gouveia, 467 U.S. 

at 192.

Ms. Diaz maintains that she suffered prejudice because the government was 

able to obtain more evidence against her and secure Ms. Cao as a witness to testify 

against her at trial. Ms. Diaz claims that the government could have indicted her a 

year earlier because the indictment of Ms. Cao for related crimes occurred a year 

earlier than her own indictment, and the evidence brought against her was 

substantially similar to the evidence used against Ms. Cao. Ms. Diaz also casts doubt 

on Ms. Cao’s discovery of a flash drive after Ms. Cao’s guilty plea, claiming that the 

late discovery was the single most damaging piece of evidence against her at trial. 

In response, the government says that the delay was based on legitimate 

investigatory reasons. One of those reasons was the collection of further evidence 

against Ms. Diaz, which included securing Ms. Cao’s testimony against Ms. Diaz. 

The government also notes that even if Ms. Diaz is correct that charges could have 

been filed against her earlier, “prosecutors are under no duty to file charges as soon 

as probable cause exists but before they are satisfied they will be able to establish 

the suspect’s guilt beyond a reasonable doubt.” United States v. Lovasco, 431 U.S. 

783, 791 (1977). Finally, the government rejects Ms. Diaz’s argument that 

collection of further evidence qualifies as prejudice. 

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Ms. Diaz did not successfully establish that the pre-indictment delay was 

deliberate or that its purpose was to gain a tactical advantage. She offered only a 

quote from her own attorney at trial, and the addition of Ms. Cao as a witness for the 

government, to prove the second prong. The prosecution waiting to secure Ms. Cao 

as a witness against Ms. Diaz was a valid reason to delay the indictment, as it was 

trying to bolster its case and wanted to be “completely satisfied that [it] should 

prosecute and will be able promptly to establish guilt beyond a reasonable doubt.” 

Lovasco, 431 U.S. at 795. Ms. Diaz, we note, also made no argument of bad faith 

on the part of the government. 

Because Ms. Diaz failed to prove the second prong, we need not reach the 

question of whether she suffered prejudice as a result of the delay. See Thomas, 62 

F.3d at 1339. Thus, the district court did not abuse its discretion by denying Ms. 

Diaz’s motion to dismiss the indictment for pre-indictment delay.

IV

Ms. Diaz argues that the district court erred when it denied her motion for 

judgment of acquittal. See Fed. R. Crim. P. 29. We review de novo the district 

court’s denial of a motion for judgment of acquittal. See United States v. Browne, 

505 F.3d 1229, 1253 (11th Cir. 2007). In doing so, we view the evidence in the light 

most favorable to the government and draw all reasonable inferences in favor of the 

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jury’s verdict. See United States v. Henderson, 893 F.3d 1338, 1348 (11th Cir. 

2018).

Ms. Diaz raises two primary arguments about the evidence presented at trial. 

First, she claims that the government failed to prove that she knew Medicare was a 

federal health care plan, and thus failed to prove an essential element of one of the 

crimes she was accused of. Second, she claims that the government failed to prove 

a conspiratorial agreement and only proved a buyer-seller relationship. She contends

that the government’s witnesses provided no evidence that she had committed a 

crime and that their testimony did not include firsthand knowledge or accounts of 

any wrongdoing. Ms. Diaz also claims that Ms. Cao’s spreadsheet was found 14

months after Ms. Cao pleaded guilty, and casts doubt on the veracity of its contents. 

And she notes alleged inconsistencies in Ms. Cao’s testimony. 

In response, the government recounts the testimony of Mr. Rodriguez, Ms. 

Aguila, and Ms. Cao. And it describes the documentary evidence of payments by 

Ms. Cao to Ms. Diaz. 

Ms. Diaz’s argument that the government failed to prove an essential element 

is unavailing. Her claim that the government needed to prove she knew Medicare 

was a federal health care plan is foreclosed by precedent: “[W]hile the government 

must prove that the United States was the ultimate target of the conspiracy under the 

defraud clause of § 371, the government is not required to allege that the United 

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States was the intended victim of a conspiracy under the offense clause of § 371.” 

United States v. Harmas, 974 F.2d 1262, 1268 (11th Cir. 1992). Thus, Ms. Diaz’s 

knowledge of Medicare’s status as a federal health care plan was not necessary for 

the jury to convict.

Ms. Diaz’s argument that the government failed to prove a conspiratorial 

agreement also fails. She is correct that, generally, a buyer-seller relationship by 

itself does not prove conspiracy. See United States v. Solomon, 686 F.2d 863, 877 

(11th Cir. 1982). What differentiates a mere buyer-seller relationship from a 

conspiratorial agreement is the “knowledge and understanding of the parties 

associated with the buying and selling.” Id. See also United States v. Mercer, 165 

F.3d 1331, 1335 (11th Cir. 1999). 

Here, the parties’ knowledge and understanding were sufficient to

demonstrate more than a mere buyer-seller relationship. Several of the witnesses at 

trial testified to Ms. Diaz’s knowledge and ongoing involvement. For example, Ms. 

Aguila testified that Ms. Diaz admitted to “moving patients” for a living and paying 

beneficiaries to go to specific health agencies. Ms. Aguila also testified that Ms. 

Diaz introduced Ms. Aguila to Ms. Cao for the purpose of referring patients to Good 

Friends in exchange for kickbacks. And Ms. Cao testified to meeting with Ms. Diaz 

in her office, where they discussed and negotiated the parameters of their 

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arrangement. Simply stated, the parameters here went beyond simple buyer and 

seller logistics. 

The evidence offered at trial was sufficient for a jury to find the existence of 

a conspiratorial agreement. The district court’s denial of Ms. Diaz’s motion for 

judgment of acquittal is therefore affirmed.

V

Finally, Ms. Diaz contests the district court’s calculation of her imprisonment 

range under the advisory Sentencing Guidelines and the overruling of her objections 

to the presentence investigation report. We review the district court’s interpretation 

of the Sentencing Guidelines de novo and the court’s factual findings underlying the 

calculation of the Guidelines range for clear error. See United States v. Barrington, 

648 F.3d 1178, 1194–95 (11th Cir. 2011). If the record supports the district court’s 

factual findings, there is no clear error. See United States v. Petrie, 302 F.3d 1280, 

1290 (11th Cir. 2002). “When a defendant challenges one of the factual bases of his 

sentence as set forth in the PSR, the Government has the burden of establishing the 

disputed fact by a preponderance of the evidence.” United States v. Lawrence, 47 

F.3d 1559, 1566 (11th Cir. 1995) (citations omitted).

Ms. Diaz made several objections to the PSR, including challenges to the 

offense conduct in paragraphs 7–19, certain factual statements in the PSR, and the 

assertion that she made false statements while testifying at trial. She also objected 

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to the following sentencing enhancements: a 16-level enhancement for the loss 

amount, a three-level enhancement for her aggravating role pursuant to U.S.S.G. § 

3B1.1, and a two-level enhancement for obstruction of justice. She claims that these 

errors resulted in a procedurally and substantively unreasonable sentence.

A

Ms. Diaz contests the district court’s application of a 16-level enhancement 

under U.S.S.G. §§ 2B1.1(b)(1)(I) and 2B4.1(b)(1)(B) due to the value of the 

improper benefit conferred. She disputes the calculation of the loss amount and 

claims that the government did not satisfy its burden to prove the amount by a 

preponderance of the evidence. Further, she argues that the loss amount should have 

only included the sums Medicare paid to Good Friends, and none of the money it 

paid to other home health care agencies. And finally, at oral argument, Ms. Diaz’s 

counsel argued that the amount should only include the amount of money she 

received as kickbacks. See United States v. Medina, 485 F.3d 1291 (11th Cir. 2007). 

In response, the government submits that the district court calculated the 

proper loss amount—$1,605,927.17—which was the “total amount that Medicare 

paid to home health agencies for patients Diaz recruited.” Appellee’s Br. at 46. The 

government also disputes Ms. Diaz’s argument that only the payments to Good 

Friends should count towards the total value. At oral argument, the government 

noted that Ms. Diaz had not previously raised her Medina argument. 

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The district court found that the government had proven a loss amount of 

greater than $1,500,000 by a preponderance of the evidence. The district court based 

the calculation of this figure on payments by Medicare to Good Friends and other 

home health care agencies. The payments to Good Friends were set out in 

Government Exhibits 539 and 604, which documented the payments from Medicare 

and received by Good Friends in Ms. Cao’s ledger. The payments made to other

home health care agencies were admitted as Government Exhibit A at the sentencing 

hearing, and Ms. Diaz did not object to the factual basis of this document. Exhibit 

A documented Medicare payments over the time period that home health care 

agencies were paying Ms. Diaz. The district court also relied on Government Exhibit 

540 to document patients whom Ms. Diaz recruited and who went to other home 

health care agencies. Ms. Aguila’s testimony also supported a finding of Ms. Diaz’s 

receipt of payment from other home health care agencies. Given this evidence, we 

conclude that the prosecution established the loss amount by a preponderance of the 

evidence and that the district court’s finding was not clearly erroneous. 

Under our precedent, payments made to other home health care agencies may 

be considered as relevant conduct in calculating the loss amount. In Nerey, for 

example, we affirmed the district court’s loss calculation in a similar Medicare fraud 

scheme where the loss calculation included fraudulent payments by Medicare to 

different home health care agencies. See Nerey, 877 F.3d at 977–78. As here, those 

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payments resulted from the defendant’s referrals to other home health care agencies. 

See id. Ms. Diaz has identified no contradictory authority on this point. 

Good Friends was not the only home health care agency to receive Medicare 

payments for Ms. Diaz’s referrals, and under Nerey, the amount paid to those 

agencies could be properly included in the loss amount calculation. The district 

court did not err in including the payments to other home health care agencies. 

Ms. Diaz’s argument that only the kickback amounts, rather than the full 

amounts paid by Medicare, should be considered in the loss calculation was waived. 

Ms. Diaz did not make this argument in her initial brief or in her reply brief, and “a 

legal claim or argument that has not been briefed before the court is deemed 

abandoned and its merits will not be addressed.” Access Now, Inc. v. Sw. Airlines 

Co., 385 F.3d 1324, 1330 (11th Cir. 2004). Raising the argument at oral argument 

for the first time was too late. See Mesa Air Group, Inc. v. Delta Air Lines, Inc., 573 

F.3d 1124, 1130 n.7 (11th Cir. 2009).

B

Ms. Diaz argues that the district court improperly imposed a three-level 

enhancement pursuant to U.S.S.G. § 3B1.1(b). According to the PSR, Ms. Diaz 

“was a manager or supervisor in a criminal activity involving five or more 

participants.” PSR ¶ 31. Ms. Diaz disputes that the government presented proof that 

satisfies the preponderance standard, and she claims that she only played a minor 

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role. Ms. Diaz’s argument concerns only whether or not the facts underlying the 

enhancement were properly found by the district court, so we review for clear error. 

See Barrington, 648 F.3d at 1194–95.

The district court found that Ms. Diaz exercised decision-making authority, 

dictated the kickback amounts, and recruited and coached her beneficiary 

accomplices. The district court relied upon Ms. Aguila’s testimony, Ms. Cao’s 

testimony, and Ms. Cao’s ledger to find that the government had met its burden. Ms. 

Aguila testified about Ms. Diaz’s payments to patients to go to home health care 

agencies for services, and both Ms. Aguila and Ms. Cao testified to Ms. Diaz 

directing the patients to clinics to receive prescriptions. Ms. Cao’s ledger also 

established Ms. Diaz’s recruitment of 150 Medicare beneficiaries. On this record, 

the district court’s aggravating role determination was not clearly erroneous. 

C

Ms. Diaz also challenges the two-level enhancement for obstruction of justice

under U.S.S.G. § 3C1.1. Ms. Diaz points to alleged discrepancies in the testimony 

of Ms. Aguila and Ms. Cao that she claims undermine the enhancement. 

Because Ms. Diaz again only challenges the facts underlying the district 

court’s application of the enhancement, we review for clear error. See Barrington, 

648 F.3d at 1194–95. The district court found that Ms. Diaz committed perjury at 

trial by a preponderance of the evidence. For example, Ms. Diaz testified that Good 

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Friends only paid her shell corporation for transporting patients. But the evidence 

at trial, including testimony from Ms. Cao and Ms. Aguila, contradicted Ms. Diaz’s 

testimony. The record supports the obstruction enhancement, and the district court’s 

ruling was not clearly erroneous. 

VI

Ms. Diaz’s conviction and sentence are affirmed. 

AFFIRMED.

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