Most ACA brokers get the same client call somewhere between February and April: a tax preparer flagged something on the 1095-A, there's a number that doesn't look right, and the client wants to know what happened. The answer is almost always one of eight reconciliation scenarios, and most of them were set up during the plan year, not at tax time.
Key Takeaways
- Form 1095-A column B contains the SLCSP benchmark premium used to calculate the full premium tax credit on Form 8962.
- An incorrect SLCSP figure in column B is one of the most common sources of reconciliation errors.
- Mid-year enrollment changes, household composition changes, and rating area moves each have their own reconciliation pattern.
- Clients who failed to report a life event during the year often face the largest gaps at filing.
- A corrected 1095-A from the marketplace, not an explanation to the IRS, is the path to fixing most source errors.
What Form 1095-A reports and why it drives reconciliation
Form 1095-A is the Health Insurance Marketplace Statement. The marketplace sends it to every client who was enrolled in a marketplace plan during the tax year, and it reports three columns of monthly data: the enrollment premium (column A), the second-lowest-cost Silver plan benchmark premium (column B), and the amount of advance premium tax credit paid on the client's behalf each month (column C).
The tax preparer takes those three columns and completes Form 8962. The premium tax credit calculation on 8962 uses the column B SLCSP figure to determine the maximum allowable credit. If the advance credit paid (column C) exceeds the calculated maximum, the difference is excess APTC that the client repays on the return. If the advance was less than the calculated maximum, the client receives the difference as a credit.
Column B is where most errors originate. An incorrect SLCSP figure propagates through the entire reconciliation because it sets the ceiling on the credit calculation. See also: the 1095-A and Form 8962 overview for brokers for the full calculation walkthrough.
The eight mismatch scenarios
| Scenario | Cause | Symptom | Resolution |
|---|---|---|---|
| 1. Wrong SLCSP in column B | Marketplace used incorrect benchmark premium, often after a mid-year plan year update or a rating area coding issue | Form 8962 credit differs from expected APTC; client either owes or is owed unexpectedly | Request corrected 1095-A from the marketplace before filing or amending |
| 2. Mid-year plan change | Client switched plans via SEP; two enrollment periods each with different column B amounts | Two 1095-A forms with gap or overlap in coverage months | Complete Form 8962 using the multi-form worksheet; verify dates align |
| 3. Household income change not reported | Client's income increased or decreased during the year without updating APTC elections | Reconciliation shows large excess or shortfall relative to what was paid monthly | No 1095-A correction needed; Form 8962 reconciles using actual annual income |
| 4. Unreported household member addition | New baby, adoption, or marriage not reported to the marketplace during the year | Family size on tax return differs from household size in marketplace records | Update marketplace application for future coverage; file Form 8962 using actual tax household size |
| 5. Divorce or household size reduction | Separation or divorce changed tax household; APTC was set based on prior household size | Two separate tax returns both reference APTC from a shared enrollment; allocation needed | Allocate APTC and premiums across returns using Form 8962 Part IV allocation rules |
| 6. Mid-year rating area move | Client moved to a different county or state and re-enrolled; two rating areas with different SLCSP | Two 1095-A forms with different column B amounts; reconciliation must handle both SLCSP values | Each 1095-A covers its own enrollment period; Form 8962 handles them as separate segments |
| 7. Employer coverage offered mid-year | Employer offered affordable coverage during the year; client remained on marketplace plan | APTC received during ineligible months creates repayment obligation at reconciliation | Identify the months of ineligibility; those months' APTC is reportable as excess on Form 8962 |
| 8. Retroactive Medicaid enrollment | Client enrolled in Medicaid retroactively for months they also had marketplace coverage and APTC | Overlapping coverage months create a period where APTC should not have been paid | Medicaid enrollment terminates marketplace APTC eligibility retroactively; reconcile through Form 8962 |
Illustrative scenarios. Tax filing requirements depend on household circumstances and current IRS guidance. Clients should work with a tax professional for filing decisions.
Scenario 1 and 2 in detail: the column B errors brokers see most
A wrong SLCSP in column B tends to be invisible to the client until the tax preparer flags it. The client received a monthly premium bill, paid the net premium after APTC, and had no reason to check the benchmark figure. The 1095-A arrives in late January, the client forwards it to their accountant, and the issue surfaces during return preparation.
The column B error is most common after mid-year plan changes. When a client enrolls through a special enrollment period, the marketplace must assign the correct SLCSP for the new enrollment. If the system pulls the wrong benchmark, the new enrollment period shows an incorrect column B for the months after the SEP. The result is a reconciliation gap that often looks like excess APTC, because the inflated column B produced a higher calculated credit than the client actually qualified for.
For mid-year plan changes resulting in two 1095-A forms, the broker's contribution is helping the client confirm the coverage month dates on both forms add up correctly. Gaps between enrollment periods create uninsured months. Overlapping dates on two 1095-A forms create a different problem: the client may appear to have received APTC for a period twice. The tax preparer needs both forms and needs the dates to be mutually exclusive.
Life events and household changes: scenarios 3 through 6
A client who had a baby, got married, or divorced during the plan year and did not update their marketplace application is carrying a household size discrepancy from the day of the life event through the end of the plan year. When the tax return uses the actual household, the APTC that was calculated on the old household size no longer matches what the family should have received.
The direction of the gap depends on which way the household changed. A client who added a dependent without updating their application likely received less APTC than they were entitled to, because the marketplace was calculating credit on a smaller family. A client who separated or divorced and did not update may have continued receiving APTC based on a larger household income split that no longer reflects the actual tax year.
The divorce scenario adds complexity at the allocation step. When a shared enrollment produced APTC and there are now two separate tax returns, the IRS requires the allocation of premiums and credits across both returns using the Form 8962 Part IV rules. The allocation split defaults to 50/50 but can be agreed on between the parties. A broker who has clients going through a separation mid-plan-year should note the date and flag that the allocation question will come up at tax filing.
Rating area moves in scenario 6 follow a cleaner path. Each enrollment period has its own 1095-A, and each uses the SLCSP from the rating area at the time. As long as the two 1095-A forms together cover the correct months with no gaps or overlaps, the reconciliation on Form 8962 can handle them through the multi-form worksheet. See also: partial-year marketplace coverage and APTC reconciliation for the mechanics of how Form 8962 handles enrollment gaps within a plan year.
Scenarios 7 and 8: eligibility changes during the year
A client who gained access to affordable employer coverage mid-year and continued receiving APTC after the offer date is collecting APTC for months when they were no longer eligible for a premium tax credit. The offer does not need to be accepted for the eligibility to shift; the availability of affordable employer coverage is the trigger. Form 8962 will flag the excess APTC for those months.
Retroactive Medicaid enrollment is the scenario that surprises clients the most. Medicaid retroactively covers the three prior months when a client becomes eligible and applies. If a client was on a marketplace plan and receiving APTC, then enrolled in Medicaid retroactively, the overlapping months produce excess APTC. The client was covered by Medicaid during those months, so they were not eligible for APTC. The amount must be repaid on Form 8962, subject to the income-based repayment caps.
For both scenarios 7 and 8, the 1095-A itself is not wrong. The form correctly reports what was paid. The reconciliation gap arises from eligibility rules, not a data error. There is no corrected 1095-A to request. The resolution is completing Form 8962 accurately and applying the correct repayment cap based on the client's income. See also: APTC repayment caps and excess APTC for the full cap structure.
What brokers can do before tax season
The most effective intervention happens during the plan year, not at filing. Clients who understand that mid-year life events need to be reported to the marketplace within 30 to 60 days are less likely to arrive at tax time with a household size mismatch. A quick reminder at the time of a life event, or a year-end check-in before the 1095-A arrives, catches most of scenarios 3 through 6 while there is still time to correct the marketplace application.
For clients who receive a 1095-A that looks wrong, the first question is whether column B matches the SLCSP for their county and plan year. A broker with access to SLCSP data can run that check quickly. If column B is off, the client needs a corrected 1095-A from the marketplace before filing. If column B is correct and the reconciliation gap comes from a life event or eligibility change, the tax preparer takes it from there.
See also: ACA silver loading and the off-Silver APTC strategy for how the benchmark Silver plan premium affects APTC calculations across all metal tiers.
Form 1095-A reconciliation FAQ
Common questions from brokers navigating client tax season APTC mismatches.
What is Form 1095-A used for?
Form 1095-A is the Health Insurance Marketplace Statement sent to anyone who was enrolled in a marketplace plan during the tax year. The three columns report the monthly enrollment premium, the second-lowest-cost Silver plan benchmark premium, and the amount of APTC paid on the enrollee's behalf. The reconciliation on Form 8962 uses all three columns to calculate the final premium tax credit and determine whether the enrollee received too much or too little APTC.
Why does column B on the 1095-A matter so much?
Column B shows the second-lowest-cost Silver plan (SLCSP) benchmark premium for each month of coverage. The IRS uses this figure to calculate what the full allowable premium tax credit would have been. If column B is wrong, the premium tax credit on Form 8962 is wrong. A column B that is too high overstates the credit and may result in excess APTC that the client owes back. A column B that is too low understates the credit and leaves money on the table.
What does a client do if their 1095-A has an error?
The client needs to request a corrected 1095-A from the marketplace. For Healthcare.gov clients, that means contacting the Marketplace Call Center or logging in to healthcare.gov and submitting a correction request. The marketplace will issue an updated form. Once the corrected 1095-A arrives, the client or their tax preparer files an amended return if the original was already submitted. The IRS will not correct the reconciliation based on a broker explanation; the corrected 1095-A is the source document.
What happens when a client has two 1095-A forms for the same year?
Multiple 1095-A forms for the same year are common when a client changed plans mid-year through a special enrollment period, moved to a different rating area, or had a plan terminated and a new one started. Each 1095-A covers a distinct enrollment period. Form 8962 has a worksheet for handling multiple forms, allocating the premium tax credit across the separate enrollment segments. Errors occur when one of the forms is missing or has incorrect dates.
Can a client receive excess APTC that they don't have to repay?
Yes. The ACA includes repayment caps that limit how much excess APTC a household must repay based on income. For 2026, the repayment cap structure depends on the household's income as a percentage of FPL. Households with income below 400 percent FPL have capped repayment amounts that scale with income. Households above 400 percent FPL repay the full excess. The Inflation Reduction Act extensions in effect for 2026 may modify how the cap structure applies at the upper income range; brokers should verify the current parameters with a tax professional.
What should a broker do when a client gets an IRS notice about their 1095-A?
An IRS CP2000 notice or similar correspondence about premium tax credit discrepancies typically means the IRS found a difference between what the marketplace reported and what was on the client's Form 8962. The broker's role is to help the client identify the likely cause, which may be a 1095-A error, an unreported life event, or a miscalculation on the original return. The response goes through the tax preparer, not the broker. If a corrected 1095-A is needed, start the request immediately because marketplace correction processing takes time.
