I’ve watched child support math get treated like gospel in a courtroom while the actual facts on the ground were a complete mess. Wrong overnight counts. Insurance premiums nobody verified. Income numbers pulled from two years ago like nothing changed. And once that worksheet becomes an order, good luck getting anyone to care that the inputs were garbage.
Colorado just passed HB25-1159, and some of the biggest changes hit on March 1, 2026. If you’re a dad in Colorado with a child support order, or you’re about to file for one, or you’re thinking about a modification, this is the kind of thing that can change your number without you even knowing it happened. Not because someone’s out to get you, but because the formula changed and nobody told you to check your math.
I’m not a lawyer. I’m a dad who spent over $250,000 and two years fighting for 50/50 custody of my son. I learned the hard way that the system doesn’t hand you information, it buries it in statutes and expects you to figure it out. So here’s what I wish someone had broken down for me, in plain English, before I ever walked into that courtroom.
This is not legal advice. This is one father’s breakdown of what HB25-1159 means in practical terms, based on the actual signed act. Talk to a family law attorney in Colorado before making any legal decisions.
What HB25-1159 Actually Is (And What It’s Not)
HB25-1159 is a bill that updates Colorado’s child support guideline calculations. It touches the math behind how support gets figured, specifically inside C.R.S. 14-10-115, which is the main statute governing child support in Colorado. The bill was signed into law on May 31, 2025, but not all of it kicks in at once.
Here’s the part that trips people up: this bill does not automatically change your current child support order. If you have an existing order, it stays the same until someone files a motion to modify it. But once someone does file that motion, or if you’re filing a new case, the new formula applies. And that new formula might spit out a very different number than the old one did.
The confusion I see constantly is dads thinking “well, nothing changed for me” because nobody served them papers. That’s not how this works. The change is in how the calculation works going forward. If your ex decides to file for a modification after March 1, 2026, the worksheet they use will be running on updated rules. If you’re not ready for that, you’re walking in blind.
Primary sources you should actually read:
- Colorado General Assembly HB25-1159 bill page
- The signed act (PDF)
- Colorado Judicial Branch child support calculator
The Dates That Matter: Passage, February 1, and March 1, 2026
This is where it gets a little layered, but stay with me because the timing is everything if you’re planning a filing.
The act became law when it was signed on May 31, 2025. But specific sections have their own effective dates built right into the legislation:
- Sections 7 and 12 took effect February 1, 2026
- Changes to C.R.S. 14-10-115(3), (7), and (8) take effect March 1, 2026
That March 1 date is the big one for most dads. Sections (3), (7), and (8) of 14-10-115 deal with the core child support calculation inputs: how income gets counted, how parenting time adjustments work, and how add-on expenses like insurance and childcare factor in. When those change, the number on your worksheet changes.
Here’s the decision question every Colorado dad should be asking right now: Am I filing or expecting a modification before or after March 1, 2026?
If you’re filing before March 1, the current formula applies. If you’re filing after, or if your ex files after, the new formula applies. And if you’re currently in the middle of a case that hasn’t been resolved yet, ask your attorney which version of the worksheet the court will use based on your hearing date. This is not a detail you want to discover at the hearing.
What Changed Inside C.R.S. 14-10-115 in Human Terms
I know statute numbers make most people’s eyes glaze over, so let me translate this into what actually matters when you’re sitting at that table filling out paperwork.
The changes in sections (3), (7), and (8) affect the inputs that go into the child support formula. Think of the formula like a calculator with a bunch of fields. The fields are things like:
- Your gross income (and how it gets calculated)
- The other parent’s gross income
- Number of overnights each parent has
- Health insurance premiums for the child
- Childcare costs
- Extraordinary medical expenses
- Extraordinary expenses for the child’s needs
When the formula behind those fields changes, even slightly, the output number changes. And here’s what kills me about this: tiny input differences create huge payment deltas. I’ve seen one wrong overnight per month swing a support number by hundreds of dollars annually. I’ve seen health insurance premiums get entered incorrectly and nobody catches it until the order’s been running for a year.
The state appropriated $56,250 to the Office of Information Technology just for programming the updated calculator. That tells you the changes to the math aren’t cosmetic. They’re structural enough that the computer system needed to be rebuilt to handle them.
Do not assume the worksheet that was used for your last order will produce the same result under the new formula. If you haven’t run your numbers through the updated calculator after March 1, you don’t actually know where you stand.
The Father’s Support Audit: 4 Boxes You Check Before Court
I put this framework together because every dad I talk to walks into child support hearings with half the paperwork they need. The court doesn’t care about what you think the numbers are. They care about what you can prove the numbers are. So here’s how you prep.
Box 1: Income Proof Pack
Gather everything that proves what you actually earn:
- Last 3 months of paystubs (or longer if your income varies)
- Most recent W-2 or 1099
- Benefits documentation (health insurance, retirement contributions)
- Overtime history (especially if it’s inconsistent)
- Any job changes in the last 12 months with offer letters and start dates
- If self-employed: profit and loss statements and tax returns
Why this matters: if you don’t bring your own income documentation, the other side gets to characterize your income for you. And I promise you, they will not be conservative about it.
Box 2: Parenting Time Proof
This is the one that gets dads wrecked more than anything else. Your overnight count directly affects the support calculation, and if the count is wrong, the money is wrong.
- Your custody order or parenting plan (the actual document)
- A calendar showing actual overnights for the last 6-12 months
- Exchange records (texts, app logs, witnesses)
- School pickup/dropoff records
- Medical appointment records showing which parent attended
- Travel receipts related to parenting time
If you haven’t been tracking this, start today. Literally today. A shared parenting app, a simple spreadsheet, even a notebook. Just document everything. The dad who can prove 146 overnights and the dad who says “I think I get about half” are in two completely different positions.
Box 3: Add-Ons Proof
Add-on expenses are where bad math hides. These are costs on top of the base support number:
- Health insurance premiums for the child (your portion AND what the other parent claims)
- Childcare/daycare costs with receipts and provider statements
- Extracurricular activity costs (if they’re being factored in)
- Extraordinary medical expenses not covered by insurance
I’ve talked to dads who were paying support that included daycare costs for daycare their kid wasn’t even attending anymore. Nobody checked. Nobody updated the number. The dad just kept paying because that’s what the order said. Don’t be that dad.
Box 4: Effective-Date Strategy
This is the new one, specific to HB25-1159. You need to know:
- What does your current worksheet look like under the old formula?
- What does it look like under the new formula (after March 1, 2026)?
- Is it better for you to file before or after the effective date?
- If the other parent is filing, when are they likely to do it?
This is a conversation you need to have with your attorney. But you can’t have an informed conversation if you haven’t run the numbers both ways first.
3 Real Scenarios Where Dads Get Wrecked (And How to Prevent It)
Scenario A: The Wrong Overnight Count
Dad has his kids 3 nights a week consistently, which is 156 overnights a year. But the worksheet from the original order says 130 because it was based on the “standard” visitation schedule, not what actually happens. Nobody updated it. Under the new formula, that 26-night difference could mean hundreds of dollars per month going in the wrong direction.
Prevention: Bring a 12-month calendar with every overnight marked. Back it up with text messages confirming exchanges. If your actual time doesn’t match what’s on the worksheet, file to correct it.
Scenario B: Phantom Expenses
The other parent claims $800/month in childcare on the worksheet. The child aged out of daycare six months ago, or switched to a cheaper provider, or grandma started watching them for free. But the worksheet still says $800 because nobody filed to update it.
Prevention: Request documentation of every add-on expense being claimed. Daycare provider statements with dates and amounts. Insurance enrollment forms showing who’s actually covered and what the premium is. Don’t take anyone’s word for the numbers, get the paper.
Scenario C: The Imputed Income Play
This is the one that makes my blood pressure spike. The other side argues you’re “voluntarily underemployed” and asks the court to impute income at a higher rate than what you actually earn. Maybe you changed careers. Maybe you went part-time to be more present for your kids. Maybe the economy hit your industry. Doesn’t matter. They’ll argue you could be making more, so you should be paying more.
Prevention: Document your job search if you’re between positions. Bring evidence of your industry’s current job market. If you took a pay cut for legitimate reasons (health, caregiving, industry downturn), have documentation. The key sentence in court: “Here is what I earn, here is the documentation, and here are the market conditions in my field.” Facts beat narratives.
Use the Official Calculator, But Don’t Let It Become Your Prison
Colorado provides a child support calculator through the Judicial Branch website. Use it. But use it strategically.
Here’s what I recommend: run the calculator twice. Once with your numbers (your actual income, your actual overnights, your actual expenses). Then run it again with what you think the other side will claim. Compare the two outputs. That delta, the gap between your version and their version, is where the fight will happen.
If the gap is small, you might be able to agree on numbers without a hearing. If the gap is huge, you know exactly which inputs to bring documentation for. Either way, you’re not walking in blind.
Remember: the calculator is only as honest as the evidence behind it. Garbage in, garbage out. And once a judge signs an order based on garbage inputs, you’re living with that number until someone files to modify it. The system isn’t designed to double-check itself.
If You Already Have an Order: What to Do in the Next 14 Days
You don’t need to panic. You need to prepare. Here’s a simple action plan:
- Pull your current order and the last worksheet. Find the actual child support worksheet that was used to calculate your current number. If you don’t have it, request it from your attorney or the court clerk.
- Run your support audit. Go through the 4 boxes above. Income, parenting time, add-ons, effective-date strategy. Figure out where your current worksheet might be wrong or outdated.
- Run the new calculator after March 1. Once the updated calculator is live, plug in your real numbers and see what comes out. Compare it to your current order.
- Talk to your attorney about timing. If a modification is on the table (either you filing or your ex filing), the timing relative to March 1 matters. Get advice specific to your situation.
- Start your war chest. Certified copies of orders, tax returns, paystubs, parenting time logs, insurance docs, daycare receipts. Put it all in one place. A binder, a folder, a fireproof safe, whatever works. If you need a system for organizing it, I wrote a step-by-step guide for preparing for custody hearings that covers the organizational side.
The point isn’t to file something right now. The point is to know your numbers so that when something does happen, whether you initiate it or someone else does, you’re not scrambling.
What I Wish Someone Told Me
When I was going through my custody battle, nobody sat me down and said “hey, the math on that worksheet matters more than almost anything else in this process.” I was so focused on custody time, on proving I was a good dad, on the emotional weight of the whole thing, that I didn’t realize the financial side was being decided by inputs I never verified.
I spent $250,000 over two years. A lot of that money went to fixing things that shouldn’t have been wrong in the first place. Wrong numbers. Wrong assumptions. Information that was outdated by the time it got in front of a judge.
If you’re a dad in Colorado reading this, please hear me: the system is not going to hand you this information. It’s not going to tap you on the shoulder and say “hey, the formula changed, you might want to check your numbers.” That’s on you. And that’s not fair, but it’s reality.
Document everything. Audit your worksheet. Ask better questions. And don’t wait until you’re standing in court to realize your numbers don’t match what’s actually happening in your life.
You don’t get a redo on a signed order. But you can walk in prepared. And sometimes that’s the difference between a number that’s fair and a number you’re stuck fighting for years.
If you’ve got questions about how child support changes are affecting dads in your state, drop them in the comments. I can’t give legal advice, but I can point you toward the right resources and share what I’ve learned the hard way.
Frequently Asked Questions
Does HB25-1159 automatically change my current child support order?
No. Your existing order stays the same until someone files a motion to modify it. The bill changes how new calculations are done, not existing orders. But if either parent files for a modification after the effective dates, the new formula will be used for the updated calculation.
What if my parenting time (overnights) is being reported wrong on the worksheet?
You can file a motion to modify child support based on changed circumstances, which includes correcting inaccurate parenting time data. Bring a 12-month calendar of actual overnights backed up by exchange records, text messages, and any co-parenting app data. The court cares about documentation, not claims.
What date do the C.R.S. 14-10-115 changes actually take effect?
The changes to C.R.S. 14-10-115 sections (3), (7), and (8) take effect on March 1, 2026. Other parts of the bill had earlier effective dates: sections 7 and 12 became effective February 1, 2026, and the act overall became effective when signed on May 31, 2025.
Where can I run the official Colorado child support calculator?
The Colorado Judicial Branch provides a child support calculator on their website: coloradojudicial.gov child support calculator. After March 1, 2026, this calculator should reflect the updated guidelines from HB25-1159. Run your numbers both before and after the update to see how the changes affect your situation.
Should I file for a modification before or after March 1, 2026?
That depends entirely on your specific situation. Run the numbers both ways (current formula vs. new formula) and consult with a Colorado family law attorney. The timing of your filing can affect which version of the guidelines applies to your case.
I’m not in Colorado. Does this affect me?
No. HB25-1159 is Colorado-specific legislation. However, most states periodically update their child support guidelines, so the principle applies everywhere: stay on top of formula changes in your state, because they can affect your number even if nothing else in your life changed.