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People usually find Form 13973 the wrong way: a search result, an old envelope, or a participant letter dug out of a drawer, and they assume it is a live credit they can still claim. It is not a tax return at all. It is the Health Coverage Tax Credit blank payment coupon, a one-page remittance slip you cut off and mail with a check, and the credit behind it expired on December 31, 2021.
That expiration is the whole story for anyone working on 2023–2025 filing tasks. If the HCTC is gone, the coupon is gone too for current purposes, and odds are good the person staring at it actually needs a different credit. The narrow exception is someone holding a real IRS enrollment notification letter and finishing a legacy payment, who mails the detached coupon with a U.S.-bank check to the HCTC lockbox at P.O. Box 970023, St. Louis, MO 63197-0023.
Key Takeaways
- IRS Form 13973 is a 1-page payment coupon, titled “Health Coverage Tax Credit (HCTC) Blank Payment Coupon” (Rev. 11-2016).
- You use it only if you received an IRS notification letter saying you successfully enrolled in the HCTC Program, and you’re submitting a payment by mail.
- The form’s process is straightforward: fill it in, print it, cut the coupon, mail it with payment to the HCTC lockbox address listed on the form.
- HCTC expired for tax years beginning after 2021, so if you’re working on 2023–2025 tax filing tasks, there’s a strong chance you’re looking for a different credit or form entirely.
- Form 13973 is not IRS e-Services, not an e-file attachment, and it does not have a signature line because it’s a coupon, not a filing.
What Is IRS Form 13973?
Form 13973 is a blank payment coupon for the Health Coverage Tax Credit (HCTC). It’s a one-page IRS PDF (Rev. November 2016) that helps the IRS apply your mailed payment to the correct HCTC participant account.
Here’s the plain-English version of what the form does:
- You enter your HCTC Participant Identification Number, name, address, and amount paid.
- You print it, cut the coupon portion, and mail it with your payment.
- The IRS uses it to process your payment accurately and faster.
The form itself says you should use it only if you received a notification letter from the IRS stating you have successfully enrolled in the HCTC Program.
The “official” Form 13973 you want
If you’re writing about Form 13973 on a blog, or using it in real life, it’s worth anchoring to the IRS source of truth:
- The IRS lists Form 13973 as: “Health Coverage Tax Credit (HCTC) Blank Payment Coupon” with revision date Nov 2016.
- The actual PDF is hosted by the IRS as f13973.pdf.
That matters because a lot of third-party sites repost IRS PDFs. Some are fine, some are sketchy, and some quietly wrap downloads in popups and “PDF editor” tools you do not want touching sensitive data.
A 2026 Reality Check: HCTC Expired, So Why Does This Form Still Exist?
This is where most online articles get sloppy.
The Health Coverage Tax Credit (HCTC) expired for tax years beginning after 2021, according to the IRS. So if you’re searching “Form 13973 for 2023” because you saw that phrase somewhere, pause. That framing is outdated.
What’s also true is:
- The IRS still hosts the Form 13973 PDF on its site.
- IRS internal guidance still discusses HCTC as a historical program and confirms there was no legislative extension past 2021.
So why might you still see Form 13973 in the wild?
Most commonly, it shows up when someone is dealing with legacy HCTC paperwork, old correspondence, or cleanup from the period when HCTC was active. The form itself ties usage to an enrollment notification letter.
If you’re working inside a firm, this is one of those moments where operational discipline matters. A weird one-page form can turn into hours of back-and-forth if your team can’t quickly confirm “what program is this tied to” and “what exactly is the IRS asking for.”
In my experience, that’s the difference between firms that scale smoothly and firms that feel like every week is a fire drill.
Who Might Still Need Form 13973?
You generally only need IRS Form 13973 if your situation matches what the PDF says:
- You received an IRS notification letter confirming you enrolled in the HCTC Program, and
- You’re sending an HCTC payment by mail, and
- You need a clean coupon the IRS can read and process.
If you didn’t receive an HCTC enrollment-related letter, this form is probably not for you.
If you’re trying to claim a current health insurance credit, this probably isn’t it
A big source of confusion is that people mix up:
- HCTC (Health Coverage Tax Credit), which the IRS confirms expired after 2021, and
- PTC (Premium Tax Credit), which is still active and is generally handled through Form 8962 when you have Marketplace coverage.
So if you’re looking for help with Marketplace insurance, Form 13973 isn’t the tool. You’re far more likely in Premium Tax Credit territory.
“Form 13973 vs IRS e-Services” (quick clarification)
It’s worth saying clearly because it’s a common misconception:
- Form 13973 is a PDF payment coupon, used for mailing a payment.
- IRS e-Services is a secure online platform used mainly by tax professionals for authorized functions (it’s not “a form you download”).
If someone is telling you to “upload Form 13973 into e-Services,” that’s a red flag that the process is being mixed up.
What You Need Before You Fill Out Form 13973
Form 13973 is short, but you still want to prep before you type anything in, especially because it deals with identifiers and payment processing.
Here’s what you should have in front of you:
- Your HCTC Participant Identification Number, pulled from your enrollment notification letter (the form explicitly points you there).
- Your name and mailing address (exactly as the program has it).
- Your payment amount.
- A payment method that the HCTC Program accepts by mail, such as:
- personal check
- business check
- certified check
- cashier’s check
- money order
A practical tip if you’re helping a client
If you’re a CPA, EA, or staff accountant supporting a client, do yourself a favor and create a tiny “proof pack” in your file:
- the IRS letter (or at least the page with the participant ID),
- the completed PDF saved with a clear filename,
- proof of mailing,
- a note in the workpaper describing what this payment was for.
That “one extra step” is the difference between a clean resolution and a messy rework cycle.
(And yes, this is the same delivery principle we see everywhere in accounting ops: structure beats heroics. When your process is consistent, your team stops getting trapped in review loops and “where is that document?” ping-pong.)
How to Complete Form 13973 Step by Step (the way the IRS designed it)
Form 13973 includes its own instructions, and they’re refreshingly direct. Here’s the clean step-by-step version, with a few real-world notes so you don’t get tripped up.
Step 1: Fill in the requested fields (ideally on your computer)
Form 13973 asks for:
- HCTC Participant Identification Number
- Re-enter HCTC Participant Identification Number
- Participant Name
- Street Address
- City, State and Zip
- Amount Paid ($)
The IRS notes that completing Step 1 electronically is recommended because it can auto-populate the coupon and improve accuracy (hand-writing the fields tends to increase processing errors, so type the data in first and print after).
Step 2: Print the document
After you fill it out, print it.
Step 3: Cut off the payment coupon
Form 13973 includes a cut line and tells you to cut off the coupon portion.
Step 4: Mail the coupon with your payment to the address on the form
The PDF lists the mailing address as:
- US Treasury – HCTC
- P.O. Box 970023
- St. Louis, MO 63197-0023
It also says: Do not send cash, and do not fold, staple, or paper clip the coupon (credit cards and electronic submission of the coupon are also not accepted – HCTC payments come in by paper check or money order only).
Payment Details That Matter (so your payment doesn’t go sideways)
The form spells out several rules that are easy to miss if you rush:
- Make checks payable to US Treasury – HCTC (not "IRS" or "United States Treasury" – the dedicated HCTC lockbox needs that exact payee to route the payment).
- Write your HCTC Participant Identification Number on your check (not your SSN – the participant ID from your enrollment letter is the only identifier that matches the payment to your HCTC account).
- Checks must be drawn from a U.S. bank (foreign-bank checks are not accepted even if they are denominated in U.S. dollars).
- Post-dated checks won’t be held for later deposit.
- Missing required info can delay processing.
If you’re doing this for a client, the “write the participant ID on the check” detail is one of those tiny things that can save weeks of cleanup later.
How to Submit Form 13973 (and what “submit” really means here)
With Form 13973, “submit” simply means:
- You mail the printed coupon along with the payment.
This is not an e-file attachment form. It’s not something you upload into a standard consumer tax filing flow.
If you’re documenting the process, treat it like any other mailed payment workflow:
- keep a copy of the completed coupon PDF,
- keep a copy (or image) of the check or money order stub,
- track mailing date and method.
Fixing Mistakes on Form 13973 (and what to do if you need to update info)
Because Form 13973 is a coupon, not a tax return, “fixing” usually means one of these:
- Don’t try to hand-edit a printed coupon. Re-do it cleanly, print again, and use the corrected coupon.
- If the check amount or participant ID is wrong, assume it can trigger processing delays. The form explicitly warns that missing/incorrect required information can delay processing.
If you’re unsure whether your situation is still tied to HCTC, remember the IRS position:
- HCTC expired for tax years beginning after 2021.
So for many people reading this in 2026, the “fix” might be confirming you’re even dealing with the right program.
Security and Privacy: Treat This Like Sensitive Tax Admin Work
Form 13973 includes personal identifiers and links directly to a payment. That’s enough to justify careful handling.
If you’re an individual, keep it simple:
- download the PDF from the IRS site,
- store it in a secure folder,
- avoid random “free PDF editor” sites.
If you’re a firm, this is where you want repeatable rules:
- role-based access to client documents,
- standardized naming,
- clear proof-of-mailing procedures,
- a checklist so nothing gets missed.
This is one place where Accountably’s operational viewpoint (delivery discipline, documentation standards, and security controls) actually belongs in the conversation, because forms like this don’t cause chaos by themselves. Chaos happens when there’s no consistent process around them.
Conclusion
Form 13973 is simple when you know what it is. It’s a one-page HCTC blank payment coupon used to mail payments tied to an HCTC enrollment notification letter.
The bigger win is avoiding the most common mistake: treating it like a normal “tax filing form” for current-year returns, when the IRS has clearly stated the HCTC expired after 2021.
Common Mistakes We See Every Season
Form 13973 is short, but the failure points are predictable – almost every mistake we see comes from treating it like a normal tax form rather than the specialized HCTC payment coupon it actually is. Six patterns repeat across the cleanup files my team handles.
Reusable Checklists
These checklists are copy-paste ready for firm SOPs or a single-engagement file – use them as starting templates and trim to your client base.
Legacy HCTC eligibility triage
- Confirm the participant holds an IRS HCTC enrollment notification letter – without it, the form has no use.
- Verify the coverage month being paid for falls on or before December 31, 2021.
- Rule out Premium Tax Credit confusion – if the client has a 1095-A and a Marketplace plan, route to Form 8962, not Form 13973.
- Capture the HCTC Participant Identification Number from the top of the IRS enrollment letter.
- Document the engagement scope as a legacy cleanup matter, not a current-year filing.
- Confirm the payment method is a U.S.-bank check or money order – cash, credit card, and foreign-bank checks are not accepted.
Coupon completion and mailing packet
- Complete Step 1 fields electronically before printing so the data auto-populates the detachable coupon.
- Re-enter the HCTC Participant Identification Number in the verification field.
- Print the form, then cut along the indicated line and mail only the detached coupon, not the instructions page.
- Draw the check on a U.S. bank, payable to 'US Treasury – HCTC'.
- Write the HCTC Participant Identification Number on the check, never the participant's SSN.
- Place the coupon and check flat and loose in the envelope – no staples, paper clips, or folds.
- Do not write below the marked line on the coupon (that strip is reserved for processing).
- Address the envelope to US Treasury – HCTC, P.O. Box 970023, St. Louis, MO 63197-0023.
- Do not post-date the check – it will be processed on receipt regardless.
Post-mail recordkeeping
- Scan the completed coupon and the front of the check before mailing.
- Use proof of mailing (certified mail or a tracked carrier) for any HCTC payment.
- File the original IRS enrollment notification letter with the engagement record.
- Retain workpapers as long as the Form 13973 contents may be material in any IRS administration, per the form's recordkeeping notice.
- Tag the file as legacy HCTC so it does not get pulled into a current-year tax workflow next season.
Keep 13973 Season From Stalling
Form 13973 does not have a busy season the way Form 941 or Form 1040 does – the HCTC under IRC §35 expired December 31, 2021 (per the IRS HCTC program page on IRS.gov), so what comes in is a slow trickle of legacy engagements: a retired client with a 2020 enrollment letter in a folder, a probate cleanup that uncovers an unpaid HCTC premium, or an audit-support file where the prior preparer never closed out the HCTC trail. The Treasury HCTC lockbox in St. Louis still processes these payments, but the workflow around them sits entirely outside the normal seasonal queue.
Because the work is irregular, it tends to land on whoever picks up the phone, and the small but specific rules (U.S.-bank check, 'US Treasury – HCTC' payee, no staples, dedicated lockbox) get missed in the rush of seasonal returns. The fix is to handle 13973 as a tightly scoped legacy procedure rather than a one-off, so the same steps repeat every time it shows up.
- Tag any incoming 13973 file as 'legacy HCTC' so it routes to a single trained preparer rather than the next available staff member.
- Lock the payee string ('US Treasury – HCTC') and the lockbox address (P.O. Box 970023, St. Louis, MO 63197-0023) into a standing template so neither gets re-typed from memory.
- Verify the HCTC Participant Identification Number against the original IRS enrollment letter before any check is cut.
- Confirm in the engagement record that the coverage period predates January 1, 2022 – the four-step coupon submission is for legacy payments only.
- Close out the file with proof of mailing and a scan of the coupon before billing, so the engagement is not reopened months later.
Accountably's U.S. tax services team handles these legacy HCTC cleanups inside the same delivery discipline we use for active forms: documented SOPs, dedicated preparer assignment, and a final review step before any payment leaves the office.
FAQs
Is IRS Form 13973 used for 2023 or 2024 tax returns?
Usually, no. HCTC expired for tax years beginning after 2021, and the IRS confirms there was no extension. If you’re dealing with a 2023–2025 tax return, you’re likely looking for a different credit or form.
Do you have to sign Form 13973?
No. It’s a payment coupon and does not include a signature line.
Where do you mail Form 13973 with payment?
The form instructs you to mail the coupon and payment to: US Treasury – HCTC, P.O. Box 970023, St. Louis, MO 63197-0023. HCTC uses its own dedicated lockbox – do not send the coupon to a regular IRS service center or general Treasury lockbox, or your payment will be delayed or misrouted.
What if I’m trying to claim the Premium Tax Credit (Marketplace insurance)?
That’s a different credit. The IRS explains the Premium Tax Credit (PTC) and notes it’s typically claimed by filing a return with Form 8962.
What is Form 8898 used for?
Form 8898 is used to notify the IRS that you became or ceased to be a bona fide resident of a U.S. territory (such as Puerto Rico, Guam, or USVI), based on IRS guidance.
What is IRS Form 8613?
Form 8613 is used by regulated investment companies to figure and pay certain excise taxes on undistributed income, according to the IRS.
What is IRS Form 8689?
Form 8689 helps a taxpayer calculate the amount of U.S. income tax allocable to the U.S. Virgin Islands in specific situations.