2025 U.S. World Trials Previews: Two-Horse Race In Men’s 200 IM With Casas & Foster

2025 U.S. NATIONAL CHAMPIONSHIPS

• Tuesday, June 3 – Saturday, June 7, 2025
• Indianapolis, Indiana
• Indiana University Natatorium
• LCM (50 meters)
• World Championship Selection Criteria
• SwimSwam Preview Index
• Meet Central
• Psych Sheets
• Live Results

MEN’S 200 IM — BY THE NUMBERS:

• World Record: 1:54.00 — Ryan Lochte (USA), 2011
• American Record: 1:54.00 — Ryan Lochte (USA), 2011
• U.S. Open Record: 1:54.56 — Ryan Lochte (USA), 2009
• World Junior Record: 1:56.99 – Hubert Kos (HUN), 2021

The men’s 200 IM is featured in the final week of our previews for the upcoming U.S. National Championships in Indianapolis, Indiana, which kick off on Tuesday, June 3rd, and run through Saturday, June 7th.

Based on what we’ve seen at the last two U.S. selection meets, we have a solid idea of how this event could shape up in Indianapolis—but a few rising stars still have the potential to make some noise beyond the two frontrunners.

TEXAS DUO THE CLEAR FAVORITES

Shaine Casas & Bob Bowman (Photo Credit: Jack Spitser)

Texas Pro Group training partners Shaine Casas and Carson Foster are the undisputed headliners in this year’s 200 IM field. They’re the only two swimmers entered who have popped sub-1:56 performances in the last seven years. The only other swimmer in the field with a career best under that threshold is Chase Kalisz, who clocked his 1:55.40 PB back in 2018.

Both Casas and Foster are adjusting to new coaching dynamics this season following the retirement of Eddie Reese, with Bob Bowman now at the helm of the Texas program. Early signs suggest both are thriving under Bowman’s guidance. Casas has showed strong progression in the freestyle this season, historically his weakest stroke in the IM, while Foster has been consistently sharp across the board.

Despite finishing runner-up to Foster at the past two Trials meets, Casas will likely enter Nationals as the favorite. His best time of 1:55.24, from the summer of 2022, ranked him 2nd in the world that year, even though he didn’t swim the event at Worlds. He’s since only been under 1:56 on one other occasion, 1:55.82 at last summer’s U.S. Olympic Trials.

Internationally, Casas has struggled to match his domestic form. He notched an outing of 1:56.35 for 4th at the 2023 Worlds in Fukuoka, 1:57.73 for 5th at the Doha Worlds in February 2024, and posted a disappointing 1:57.82 in Paris, missing the final altogether with a two-second add from Trials.

However, Casas appears to have turned a page under Bowman. At the 2024 Short Course World Championships, he clocked a new American Record of 1:49.51, becoming the 2nd-fastest man in history in the short course 200 IM behind only world record holder Leon Marchand, and winning the title by over a second and a half.

This season, he’s been as quick as 1:56.52, currently the fastest American by half a second. While that’s still a bit off his lifetime in-season best of 1:56.06 (done under Reese in 2023), Casas has never been known for massive drops at taper meets, until now. His across-the-board bests at the 2024 SC Worlds suggest the Bowman effect could result in championship drops that he previously lacked. If that repeats in Indianapolis, the rest of the field could be in major trouble.

The biggest yellow flag? Consistency. Casas has a well-documented history of peaking during in-season meets or ‘B’ finals. He sometimes misses A-finals altogether, then turns around and wins the B-final with a time that would’ve won the main event. See the 2023 U.S. Open for textbook examples. That volatility makes him tough to place in these prediction scenarios.

Foster, on the other hand, is a reliable bet. He’s the two-time defending U.S. Trials champion and has consistently thrown down 1:56 swims on demand. Given that track record, it’s hard to bet against him making the team again, and almost harder to bet against a three-peat. Still, Casas’ form this season is difficult to ignore.

Over the last three seasons, Foster has gone under 1:57 an incredible 12 times. His two sub-1:56 swims came in the 2022 World Championship final, where he won silver in 1:55.71, and at the 2024 U.S. Olympic Trials, where he went a personal best of 1:55.65.

Foster finished 5th at the 2023 Worlds in 1:56.43, and was upset at the 2024 Worlds by Canadian Finlay Knox, settling for silver in 1:56.97 despite entering as the favorite in Marchand’s absence. He then placed 4th at the Paris Olympics in 1:56.10, just a tenth behind the bronze medalist.

Foster’s 1:57.04 from the Westmont Pro Series in March is not only his current season best but also his third-fastest in-season performance ever. That mark only trails the 1:56.51 and 1:56.80 he notched in May and June of 2023, respectively, and just edges out the aforementioned 1:56.43 he recorded at Worlds.

Another mid-1:56 should see Foster make his fifth-straight international long course appearance in the event, but if he is able to get back into the 1:55 range then we could be in for an exciting battle if Casas is in good form.

WHAT ABOUT THE 2017 WORLD CHAMPION?

Chase Kalisz (Photo Credit: Jack Spitser)

While Shaine Casas and Carson Foster have recent momentum, Chase Kalisz has long brought unmatched experience to the 200 IM. His lifetime best of 1:55.40, set at the 2018 Pan Pacific Championships, ranks him #6 all-time among Americans, just ahead of Foster. Kalisz won this event at the 2022 U.S. World Trials and represented the U.S. in the 200 IM at the 2017, 2019, and 2022 World Championships, as well as the Tokyo Olympics, where he took gold in the 400 IM.

However, Kalisz will not be racing the 200 IM at this year’s Nationals. Since the Paris Olympics, where he touched 11th in the 400 IM, he has competed just once—at the COPA Internacional in Veracruz, Mexico this past February—where he swam only non-IM events: the 100 breast (1:04.63), 100 fly (54.97), and 200 fly (2:00.03), all far off his career bests.

Kalisz peaked in the 1:55 range back in 2017 and 2018, and while he hasn’t returned to that form in recent years, he’s remained one of the top Americans in the event. He hasn’t finished outside the top 3 among U.S. swimmers since 2015. With his absence this season, the path is clearer than ever for the next generation to take over, especially if either Casas or Foster falters.

Chase Kalisz – 200 IM

THE HEIR APPARENT

Speaking of that new generation…Maximus Williamson has been rapidly rising through the age group rankings over the last few years, and hit a new gear in the long course pool at the 2023 World Junior Championships.

In this event, Williamson claimed gold in 1:57.29, making him the fastest 17-year-old in history and the #2 performer all-time in the U.S. boys’ 17–18 age group, trailing only Michael Phelps (1:55.94).

Relative to the rest of the field at Trials, Williamson’s skillset most closely resembles Foster’s—he’s well-rounded across all four strokes, with breaststroke being his relative “weakness.” What sets Williamson apart, however, is his ability to close. He’s clocked sub-27.5 on the final 50 multiple times—a finishing split that’s very rare among young swimmers, let alone most of the top-level senior athletes.

At last summer’s Olympic Trials, the Virginia commit had a slight misfire: after notching 1:58.58 in prelims, he touched 9th in the semis at 1:58.59, narrowly missing a lane in the ‘A’ final.

Now 18, Williamson has only swum the long course 200 IM once so far this season, hitting a 2:09.60 prelim at the MAC Senior Meet just two weeks ago. He scratched that final, so there isn’t a clear picture of his current true form. For comparison, in the lead-up to Olympic Trials last year, he posted 2:00.90 and 2:01.00 at two Pro Swim Series stops before falling to a 2:04.84 at a local meet in May. He’s always been known as a big-time taper swimmer, so all of these in-season results should be taken with a grain of salt.

Williamson has dropped from 1:59 to 1:58 to 1:57 across the last three seasons, with his 1:57 technically coming just after the end of last season, and if that trend continues and he posts a 1:56 in Indianapolis, a Worlds roster spot can’t be completely ruled out.

BEST OF THE REST

Kieran Smith has the fastest lifetime best of the remaining entrants, having gone as fast as 1:56.97. Most likely, this will be a “bonus” event for him after qualifying in one or more freestyle events, but it’s worth remembering that he placed 3rd at Olympic Trials in this event in both 2021 and 2024—behind only Michael Andrew and Kalisz in ’21, and Foster and Casas last year—en route to clocking a lifetime best in both finals.

His season best stands at 1:59.01 from the Fort Lauderdale Pro Swim Series earlier this month. He’s been under 2:00 on three occasions since April 15 and is currently half a second ahead of his 2024 season best (1:59.52), prior to clocking his personal best at Trials. He appears to be on track to notch another lifetime best, especially with his history of dropping significant time with taper.

Cal’s Destin Lasco could also be a factor here. He posted a personal best of 1:57.97 at the 2023 U.S. Nationals, but his best shot at the Worlds team lies in the 4×100 free relay and the 100 and 200 backs. He has not swum the 200 IM since placing 11th at last summer’s Trials in 1:58.77.

Indiana’s Owen McDonald, who spent his first two seasons at ASU before transferring to IU, was 5th at Trials last summer with a 1:57.51. He has three strong legs—24.8 on fly, 28.8 on back, and 27.3 on free—but his 36.3 breaststroke split remains a major liability. However, IU is known for rapidly developing breaststrokers, and if he can chop off a second and a half on that leg in the next few years, he could be a legitimate contender heading toward the 2028 Los Angeles Games. His season best rests at 2:01.96 from mid-April.

Sun Devil pro Grant House, McDonald’s former training partner, has looked sharp all season. He posted a 1:58.22 at the Sacramento Pro Series stop in early April, just a hundredth off his 1:58.21 lifetime best from July 2023. While his top shot at the team remains a top-6 finish in the 200 free, a sub-1:58 showing and a place in the upper half of the ‘A’ final is well within reach for the 26-year-old based on his current form.

Another international team veteran, Trenton Julian, is the only other swimmer in the field who has been under 1:58. His best of 1:57.86 comes from the 2021 Speedo Summer Championships – West. He nearly matched that time at 2023 Nationals with a 1:57.94, finishing 3rd in a tight battle with Casas, Lasco, and Smith. He clocked a 2:00.24 at last summer’s Trials for 15th in prelims before scratching the semifinals. So far this season, he has only contested the event once, at the Pro Swim Series stop in Westmont, where he posted a pair of swims in the 2:03 range.

Other NCAA standouts to keep a keen eye on include:

• Daniel Diehl (1:58.62) — The 2023 World Junior silver medalist behind Williamson, NC State sophomore Diehl set his personal best of 1:58.62 at that meet. Like Lasco and House, his best shot at making the team may come in a relay, most likely the 4×200 free, if he can improve upon his 9th-place finish from last summer’s Trials, where he clocked a PB of 1:46.83. He’s also in the mix for both backstroke events, with the 200 representing his better chance. Diehl didn’t swim the 200 IM at last year’s Trials due to a schedule conflict with the 200 back, but that conflict no longer exists, so we should see him rejoin the event this time. He has yet to race it in long course this season.
• Will Modglin (1:58.44) — Now also training at Texas, Modglin’s best chance at a roster spot likely lies in the 100 back. That said, the 200 IM, scheduled on the final day, could serve as a bonus opportunity. The sophomore hasn’t raced the event in long course yet this year, but popped a personal-best 1:58.44 for 8th in last year’s Trials final. 
• Nate Germonprez (1:58.11) – Texas sophomore Germonprez will likely be targeting the wide open sprint breaststroke events. Like Modglin, he hasn’t raced the 200 IM in long course yet this season, but he could still pose a threat based on 1:58.11 best time from last July, though since shifting his focus more toward breaststroke, his IM has trended in the wrong direction. 
• Baylor Nelson (1:59.13) — Recently transferred to Texas from Texas A&M, Nelson owns the slowest PB of this group, but he’s already been 2:00.50 this season and looks ready to lower his lifetime best from July 2022. That kind of form could put him right on the edge of an ‘A’ final berth. He’s already a World silver medalist, having contributed a prelims swim on Team USA’s 4×200 free relay at the 2023 World Championships.

Remember, this is not a comprehensive list of swimmers to watch—several other NCAA athletes could toss their names into the hat for an ‘A’ final berth—but these are some of the primary contenders to keep an eye on as the action gets underway next week.

SwimSwam’s Picks

Darkhorse: Michael Hochwalt — The Arizona State freshman has adapted quickly to his new training environment in Tempe, collecting numerous personal bests throughout his first NCAA season. He carried that momentum into the long course pool at the Sacramento Pro Swim Series, held just about a week after NCAAs, where he won the 400 IM in a lifetime best of 4:16.88. Perhaps more notable, though, was his 200 back/200 IM double: he touched 2nd in the 200 IM in 2:00.08 before clocking another runner-up finish in the 200 back at 2:00.19—just about 10 minutes later. The IM time clipped his previous best of 2:00.92 by nearly a second, while the backstroke performance fell just one hundredth off his own mark of 2:00.18 despite coming on the heels of a full-effort IM. At Nationals, the 200 IM falls on the final day and won’t overlap with the 200 back (which occurs earlier in the meet), meaning he’ll be able to focus entirely on one race.