What's Driving ICCSD Enrollment?

A factor-by-factor decomposition, 2011–2025  ·  Iowa DOE BEDS PK-12 headcount

ICCSD grew +2,466 students (PK-12) from 2011-12 to 2025-26 — but it would have grown +2,965 students if it had simply held its 2011 share of a growing Johnson County. The ~499-student gap is almost entirely explained by Tiffin/Clear Creek Amana absorbing new residential growth that would otherwise have flowed to ICCSD. On top of that, post-2023 ESA transfers add a newer, smaller headwind. Looking forward, declining birth cohorts are the dominant risk.
County demographic tailwind
+2,964
Students ICCSD gained from county growth (at 2011 share)
CCA geographic capture
-498
Annual gap vs. 2011 share (2025-26)
ESA net transfers (2025-26)
≈ −130
Public→private switchers (9 % of 1,440 residents)
Open enrollment (net, 2025-26)
+15
More CCA/Solon residents now choose ICCSD than vice versa

The 14-Year Walk (2011-12 → 2025-26)

The bar below shows how ICCSD enrollment changed from its 2011-12 base. Two factors explain essentially everything: Johnson County grew (green), but CCA/Tiffin absorbed a disproportionate share of that growth (red).

Enrollment bridge — 2011-12 to 2025-26 (PK-12 headcount)

Sources: Iowa DOE BEDS Public enrollment files, 2011-12 through 2025-26. Counterfactual = ICCSD at its 2011-12 county share (77.1%) applied to each year's Johnson County total public enrollment.

What this means: Johnson County's public school enrollment grew by 3,846 students over 14 years. At ICCSD's 2011 share, it would have captured 2,965 of those — instead it captured 2,466. The missing 499 students per year (by 2025-26) sit inside Clear Creek Amana CSD.

Johnson County Share — How It Shifted

District share of Johnson County public PK-12 enrollment

All Johnson County public school districts. The CCA share gain mirrors the ICCSD share loss almost exactly; Solon is flat.

Each Factor, Explained

① County Population & In-Migration
+2,965 students
Johnson County's public K-12 enrollment grew 24 % from 2011 to 2025, driven by University of Iowa employment growth, hospital and biomedical sector expansion, and general in-migration from outside Iowa. ICCSD benefited proportionally — this is the demographic tailwind that lifted all boats.
② Immigrant & ESL Student Growth
~+900 students (est.)
Johnson County immigrant students grew from roughly 20 in 2009-10 to ~1,164 in 2020-21 (Iowa DOE). ICCSD captures roughly 78 % of county public enrollment, implying ~900 incremental students from this cohort alone. This is embedded in the county growth figure above — without immigration, the tailwind would be significantly smaller.

Forward risk: immigration-policy uncertainty could reduce or reverse this cushion with a 3–5 year lag into K-12 enrollment.
③ CCA / Tiffin Geographic Capture
−499 students/yr (2025-26)
Clear Creek Amana CSD (containing Tiffin) grew 79 % from 2011 to 2025 while ICCSD grew 20 %. New subdivisions in Tiffin — larger lots, newer construction, lower price per square foot — attract Iowa City-area families, who then enroll in CCA.

Critically, no transfer event occurs: many of these families moved to Tiffin before having children, or relocated directly from out of state. The loss is invisible to open-enrollment data and only measurable via the BEDS headcount gap.
④ ESA Net Transfers (2023+)
≈ −130 students/yr (2025-26)
Iowa's ESA (Educational Savings Account) voucher program launched in 2023. ICCSD has 1,440 resident ESA users in 2025-26, but the district's own analysis found ~78 % were already attending private school (inframarginal). Net public→private switchers are estimated at ~120–190 over three years, or roughly 130 in the current year.

ESA is separate from the county-share analysis above because private-school students leave the county BEDS total too. ESA is an additional drag on top of the geographic capture figure.
⑤ Open Enrollment (Now Net Positive)
+15 net (2025-26)
Students from neighboring districts (CCA, Solon, others) can open-enroll into ICCSD and vice versa. In 2017-18, ICCSD was losing 272 students more than it gained on net. By 2023-24 the balance flipped positive. CCA went from +161 net in 2017-18 to −104 net in 2025-26 — its own residents are increasingly choosing ICCSD.

This is a direct signal: families with an active choice are choosing ICCSD more than before, ruling out district-quality flight as a driver of enrollment pressure.
⑥ Birth Rate — The Forward-Looking Driver
−600 to −900 by 2030 (est.)
Johnson County births peaked around 2007-2011. Students born in those high-birth years are now 14-18 and approaching graduation; smaller cohorts born 2014-2020 are entering kindergarten. This "pipeline" effect — not ESA, not transfers — is the primary driver of the projected enrollment decline through 2030.

Three independent forecasts (Iowa DOE 2026 projections, Woolpert 2025, this model's baseline) all converge on ICCSD K-12 enrollment of ~13,475–13,720 by 2030-31.

Enrollment Over Time — ICCSD, CCA, Counterfactual

PK-12 headcount: ICCSD actual vs. constant-share counterfactual, and CCA

Counterfactual line = ICCSD enrollment if it had held its 2011-12 county share each year. COVID-related anomaly visible in 2020-21 (ICCSD −511, CCA +73).

Full data table

SY ICCSD At 2011 Share Gap ICCSD % CCA CCA % County Total
2011-12 12,405 12,405 +0 77.0% 1,779 11.1% 16,099
2012-13 12,751 12,796 -45 76.8% 1,919 11.6% 16,607
2013-14 13,215 13,260 -45 76.8% 2,022 11.8% 17,208
2014-15 13,397 13,502 -105 76.5% 2,103 12.0% 17,523
2015-16 13,666 13,763 -97 76.5% 2,199 12.3% 17,862
2016-17 13,986 14,140 -154 76.2% 2,331 12.7% 18,351
2017-18 14,405 14,581 -176 76.1% 2,492 13.2% 18,923
2018-19 14,560 14,814 -254 75.7% 2,633 13.7% 19,226
2019-20 14,939 15,181 -242 75.8% 2,750 14.0% 19,701
2020-21 14,428 14,819 -391 75.0% 2,823 14.7% 19,232
2021-22 14,820 15,229 -409 75.0% 2,975 15.1% 19,764
2022-23 14,806 15,271 -465 74.7% 3,061 15.4% 19,818
2023-24 14,776 15,305 -529 74.4% 3,126 15.7% 19,862
2024-25 15,013 15,447 -434 74.9% 3,156 15.7% 20,047
2025-26 14,871 15,369 -498 74.6% 3,190 16.0% 19,945

Open Enrollment — Net Position

Open enrollment records students who cross district lines by choice while remaining a resident of the sending district. Families who moved to Tiffin are invisible here — this chart shows only active-choice transfers.

Net open enrollment (OE In − OE Out): ICCSD and CCA

Source: Iowa DOE Certified Enrollment by District (Row 8 minus Row 2). Positive = net receiver.

Why this matters: If families were fleeing ICCSD for CCA due to quality concerns, ICCSD's net open-enrollment would be falling and CCA's would be rising. The opposite happened. ICCSD flipped from −273 net in 2017-18 to +15 in 2025-26; CCA flipped from +162 to −104. The enrollment pressure on ICCSD is a housing geography story, not a quality story.

ESA in Context

ESA resident users
1,440 (2025-26)
ICCSD-resident students using an ESA, per Iowa DOE certified enrollment Row 14. Up from 471 in 2023-24.
Net public→private switchers
~130 est. (2025-26)
~78% of ESA users were already attending private school (inframarginal). Net new transfers from ICCSD public ≈ 120-190 over 3 years total.
CCA geographic capture (2025-26)
499 students/yr
The geographic headwind is roughly 4× larger than ESA on an annual basis and has been compounding since 2011.
CCA cumulative (2011-2025)
~4,100 student-years
Cumulative student-years of foregone enrollment at constant county share. At ~$9,000 state aid/student: ≈$37M in foregone foundation aid since 2011.

More on ESA. The full funnel from 1,440 vouchers down to about 120 to 190 real public-to-private transfers is broken out in the ESA decomposition page →

Looking Forward (2025–2030)

The birth-rate cliff: Johnson County births peaked around 2007-2011. Students born in those peak years are graduating now. Smaller cohorts born 2014–2020 will shrink kindergarten classes through ~2025-2030. Three independent forecasts converge on ~13,475–13,720 ICCSD enrollment by 2030-31 — a decline of roughly 800–900 students from the 2024-25 certified enrollment of ~14,550. At $9,000/student in state foundation aid, that is a ~$7–8M annual revenue headwind.
Birth cohort decline
−600 to −900 by 2030
Primary driver of projected decline. Already "baked in" — the children who will be in K-12 in 2030 are already born.
Continued CCA growth
−50 to −100/yr additional
Tiffin construction pipeline continues; CCA's share likely to reach 17-18% of county by 2030. Further structural drag on ICCSD headcount.
ESA trajectory
−50 to −150 additional
ESA enrollment is growing. The inframarginal share may shrink as the pool of "already-private" families is exhausted, increasing marginal impact.
Immigration cushion
Positive but uncertain
Johnson County's immigrant student influx has been a meaningful offset. Federal immigration policy changes could reduce this cushion with a 3–5 year lag.

→ Full enrollment forecast with three scenarios (Baseline, High, Low)