Employer Mandate Penalties: 4980H(a) and 4980H(b)

Internal Revenue Code sections 4980H(a) and 4980H(b) establish the two distinct penalty structures that apply when an Applicable Large Employer (ALE) fails to meet its coverage obligations under the Affordable Care Act. These penalties — commonly called the "A penalty" and the "B penalty" — differ in their trigger conditions, calculation methods, and potential dollar exposure. Understanding how they interact is essential for any ALE navigating ACA compliance and the broader regulatory context for ACA.

Definition and scope

Section 4980H of the Internal Revenue Code, enacted as part of the ACA and administered by the Internal Revenue Service (IRS), imposes an Employer Shared Responsibility Payment (ESRP) on ALEs that either fail to offer coverage or offer coverage that does not meet minimum standards. An ALE is any employer with at least 50 full-time employees, including full-time equivalents, during the prior calendar year (IRS, Employer Shared Responsibility Provisions).

The two penalties operate independently but share a common prerequisite: at least one full-time employee must receive a premium tax credit (PTC) through the ACA Marketplace. Without a PTC trigger, no penalty is assessed under either subsection.

For a structured overview of how ALE status is determined — including the measurement rules that govern which employees count — see the ACA authority index for links to full-time equivalent counting guidance and controlled group rules.

How it works

4980H(a) — The "A Penalty" (Failure to Offer)

The 4980H(a) penalty applies when an ALE fails to offer minimum essential coverage (MEC) to at least 95% of its full-time employees (and their dependents) for a given month, and at least one full-time employee receives a PTC.

The penalty is calculated on a per-month, per-employee basis using a formula keyed to the full ALE workforce:

  1. Determine the total number of full-time employees for the month.
  2. Subtract 30 (the statutory offset).
  3. Multiply the remainder by 1/12 of the annual penalty amount.

For plan years beginning in 2024, the annualized 4980H(a) penalty rate is $2,970 per full-time employee (after the 30-employee reduction) (IRS Rev. Proc. 2023-29). This rate is indexed for inflation annually.

4980H(b) — The "B Penalty" (Failure to Provide Affordable/Minimum Value Coverage)

The 4980H(b) penalty applies when an ALE does offer MEC to at least 95% of full-time employees, but the coverage offered to a specific employee either:
- Is not affordable under the applicable IRS affordability standard, or
- Does not provide minimum value (MV) — meaning the plan pays less than 60% of covered costs.

Unlike the A penalty, the B penalty is assessed only on the specific employees who receive a PTC — not on the full workforce. The 2024 annualized rate is $4,460 per affected full-time employee (IRS Rev. Proc. 2023-29), but the total B penalty for any employer is capped at the amount that would have been owed under the A penalty formula.

Common scenarios

Scenario 1 — Full coverage gap (A penalty)
An employer with 200 full-time employees offers no health plan at all. Two employees receive PTCs. The A penalty applies: (200 − 30) × ($2,970 ÷ 12) = approximately $42,075 per month, regardless of how many employees received PTCs.

Scenario 2 — Unaffordable coverage (B penalty)
An employer with 200 full-time employees offers MEC to all full-time employees, but the employee contribution exceeds affordability thresholds. Eight employees receive PTCs. The B penalty applies to those 8 employees only: 8 × ($4,460 ÷ 12) ≈ $2,973 per month — substantially less than the A penalty cap of $42,075.

Scenario 3 — Coverage offered to insufficient percentage (A penalty)
An employer offers coverage to only 90% of full-time employees, falling below the 95% threshold. Even if the plan itself is affordable and meets MV for those who receive it, the 4980H(a) penalty applies to the entire workforce (minus 30), not just uncovered employees.

Scenario 4 — Dependent-only gap
An employer offers compliant self-only coverage but fails to extend any offer to employee dependents. Depending on the plan year, this can trigger A penalty exposure because the ACA requires offers to extend to dependents (children up to age 26) as part of the coverage obligation.

Decision boundaries

The selection between A and B penalty exposure turns on a structured set of conditions. Employers and compliance teams typically apply the following logic:

  1. Did the ALE offer MEC to ≥ 95% of full-time employees and their dependents?
  2. No → 4980H(a) applies if any full-time employee receives a PTC.

  3. Yes → Move to step 2.

  4. Was the coverage affordable under the applicable IRS safe harbor?

  5. The 2024 affordability threshold is 9.02% of household income (IRS Rev. Proc. 2023-29). Because household income is not directly known to employers, three IRS-approved safe harbors — W-2 wages, rate of pay, and federal poverty line — provide defensible affordability calculations.
  6. No → 4980H(b) applies to each full-time employee who receives a PTC.

  7. Yes → Move to step 3.

  8. Does the plan provide minimum value?

  9. Coverage must cover at least 60% of the total allowed cost of benefits (IRS minimum value rules under §36B).
  10. No → 4980H(b) applies to each full-time employee who receives a PTC.
  11. Yes → No ESRP liability, provided the employee did not nonetheless qualify for a PTC on other grounds.

A critical distinction between the two penalties: the A penalty can generate a larger total liability because it scales with the entire workforce minus 30, while the B penalty scales only with affected individuals — though its per-employee rate is higher. For an employer with a large workforce and widespread coverage gaps, 4980H(a) exposure can exceed 4980H(b) exposure by an order of magnitude.

Penalty assessments are initiated by the IRS through Letter 226-J, which notifies ALEs of proposed ESRP liability. The 226-J process includes a defined response window and an opportunity to dispute calculations before a final assessment is issued.

References

The law belongs to the people. Georgia v. Public.Resource.Org, 590 U.S. (2020)